Newbie Here: Advice On Transplanting A 455 Olds In A 1979 Formula?

[theplummer]

Howdy all,

We recently came across a really well taken care of 79 Formula, with 86K miles.
The 301 has got to go though.

Here's the plan. Salter Racing Engines is starting to build a 455 Olds for us. It's going to be stroked to 500ish cubes and will spin at least 6500 RPM's and should easily break the 600 lb/ft Torque and Hp barrier.

Here's the deal, I'm sure we are going to have fitment issues, particularly with the factory AC box and valve cover area. Also, this engine is getting a Edelbrock High Rise 2810 Intake manifold, so I know were going to have hood clearance issues.

I despise the way aftermarket hoods look, so, the plan is to take a 69 Yenko Camaro 'Sniper' cowl hood and graft it to a base model Firebird hood, and paint it flat black.
I think it'd be cool looking on a white/grey/blue Formula.

This engine comes with a matching Turbo 400 also. The plan so far is to upgrade the 400 with a 2500 'lock up' stall converter and just beef up the factory rear end.

From what I understand 403 Olds motor mounts will work with the 455, but I'm thinking that I might be able to build some custom mounts and lower the engine until it's almost touching the crossmember to help with the clearance issues.

Any advice before we get too deep into this project would be appreciated... I'm trying to plan ahead as much as possible, so any hints or tricks would be appreciated.

 

[theplummer]

Geez, Apologies.. I said "Sniper' cowl hood.. When I meant to say 'Stinger'...
Boy, that doesn't bode well for a first post as a newbie, does it? Sorry guys.

 

[Munkyslut]

Geez, Apologies.. I said "Sniper' cowl hood.. When I meant to say 'Stinger'...
Boy, that doesn't bode well for a first post as a newbie, does it? Sorry guys.

…… we don’t care about mistakes

 

[theplummer]

So, I found a donor used flat 77-81 Firebird hood, for a $100 on Markeplace. but it was 150 miles away. So I loaded up and headed out in the Yukon Denali this morning.... Did you know that a Firebird hood won't fit inside a Yukon? I didn't... But, I do now...

The guy was really nice, he offered to give me my money back and I could come back with a trailer.. I said, "I ain't coming back here again, you got a cutoff wheel? He said, "Why?"
Me: "Because I'm going to cut the damn thing in half, it'll fit then." he laughed. I said that I was serious.

So, while I'm cutting the hood in half, he's saying that he's seen it all now... He's never had anyone buy a body part from him, then proceed to cut it up, just so he can get it home.

Then I showed him a picture of the Camaro stinger cowl hood and that I only need about 6" all the way around the outside of the Firebird hood. Then he understood.

 

[Munkyslut]

From memory the Olds 455 is about 1” taller & 1.5” wider than the 350/403 blocks.
I have a feeling the engine mount lugs are in the same position on all the blocks regardless of small or big, I could be mistaken.
My brother had a 75 Trans Am here in England about 30 years ago that had a 455 Olds in it. What was more interesting was that it was also a 4 speed, was a fun car!
It had headers (couldn’t tell you what brand) but I don’t remember any clearance issues whatsoever, even the original shaker & associated air filter were used. I’m assuming the Olds intake is lower than the equivalent Poncho, maybe that would explain it.

 

[chuckitall]

Munky is correct, although they look the same, there is actually a small block and big block Olds. I believe the 455 and 425 are big blocks, and the deck is in fact taller (the distance from the crank center-line to the deck). Not sure if it will make a difference as far as fitting of the A/C system, if you choose to keep it. I would highly recommend seeking out an Old powered Trans Am for a parts car. If you know anyone that has a factory Olds T/A, look one over very closely. When they put Olds motors in them, the engine is actually offset to the passenger side of the car, I would guess to clear the steering box, so the shaker scoop-to-air filter is off center as well (but you won't have to worry about the scoop). You can see this if you're ever at a car show and see two T/A's sitting side-by-side, one Pontiac and one Olds powered. All this may not be that big of an issue, but not sure if you will be able to drop it down closer to the frame, never really paid attention to the oil pan-to-frame clearance of the Olds cars. Sounds very interesting, keep us updated on how it turns out !
On an interesting side note, I have seen two different T/A's (one at the Trans Am Nats in Dayton Oh, and the second at a car show at Summit Racing in Akron Oh) both had '69 Buick GS 400's in them. Both owners had the same issues, the first was the Buick was too wide to install the A/C compressor, the second was the Buick produces so much low end torque that the would rip the teeth off the rig/pinion of the stock 10 bolts !! But both were quite happy with the performance !

 

[theplummer]

From memory the Olds 455 is about 1” taller & 1.5” wider than the 350/403 blocks.
I have a feeling the engine mount lugs are in the same position on all the blocks regardless of small or big, I could be mistaken.
My brother had a 75 Trans Am here in England about 30 years ago that had a 455 Olds in it. What was more interesting was that it was also a 4 speed, was a fun car!
It had headers (couldn’t tell you what brand) but I don’t remember any clearance issues whatsoever, even the original shaker & associated air filter were used. I’m assuming the Olds intake is lower than the equivalent Poncho, maybe that would explain it.

I've been told the 403 motor mounts will work. Can't find any just yet. Looking for used ones.

 

[Maxthe222]

Yep, the advice from me is, don't swap in a 455 Olds. One of the worst swaps you can do for a second gen Firebird as there are so many better options you can choose. Like you have mentioned, you're going to have a lot of fitment issues and you'll come to find none of the accessories and most aftermarket parts will not help you at all.
The factory 403 Olds mounts are the same as many others and will still fit to the block fine, but the block is still substantially taller than the small-block 403 Olds so it's not just taller, it's even more offset and not centred with the Firebird hood ridge. They are a couple of dollars new on RockAuto, they are very cheap and common. There is not point getting used mounts when new ones are very cheap. The mounts are already very short, there's very little fat you can trim off them to lower them further.

Even if you graft on that aftermarket cowl hood thing, the 455 Olds will sit in a weird way where if you were looking down the center of the carb, it would be further off to the right, and that's with a standard cast iron manifold. It might not be enough to fully cover it. Keep in mind as well, the TH400 is larger than the TH350, and will also sit differently in the transmission tunnel, and might give you even more clearance issues with the HVAC box and exhaust.

I had a 1979 Firebird Esprit that was originally a 305 2bbl that had an Olds 455 swapped in it, fitment was abysmal, ended up parting the car out.

 

[theplummer]

Yep, the advice from me is, don't swap in a 455 Olds. One of the worst swaps you can do for a second gen Firebird as there are so many better options you can choose. Like you have mentioned, you're going to have a lot of fitment issues and you'll come to find none of the accessories and most aftermarket parts will not help you at all.
The factory 403 Olds mounts are the same as many others and will still fit to the block fine, but the block is still substantially taller than the small-block 403 Olds so it's not just taller, it's even more offset and not centred with the Firebird hood ridge. They are a couple of dollars new on RockAuto, they are very cheap and common. There is not point getting used mounts when new ones are very cheap. The mounts are already very short, there's very little fat you can trim off them to lower them further.

Even if you graft on that aftermarket cowl hood thing, the 455 Olds will sit in a weird way where if you were looking down the center of the carb, it would be further off to the right, and that's with a standard cast iron manifold. It might not be enough to fully cover it. Keep in mind as well, the TH400 is larger than the TH350, and will also sit differently in the transmission tunnel, and might give you even more clearance issues with the HVAC box and exhaust.

I had a 1979 Firebird Esprit that was originally a 305 2bbl that had an Olds 455 swapped in it, fitment was abysmal, ended up parting the car out.

What do you mean by offset? Are the motor mounts moving the engine to the driver's side? I ask because the Intake carb flange is centered in the lifter valley. I would think that would cause interference with the steering shaft and gear box. I know that's going to be an issue with headers already. Snaking them past the steering shaft.

 

[chuckitall]

What we mean by off-set is the entire engine and transmission assembly not centered in the car. I guess the easiest way to try to visualize it is, if you were to take off the hood of an Olds powered F-car, stood on the roof of the car and looked straight down at the engine, the centerline of the engine is not in the middle of the car. It is slightly mounted to the passenger side, like I said, probably to clear the steering gear. This practice was not uncommon, especially during the seventies when GM started mixing engines. While working at some of the dealers I worked for, I saw all kinds of wacky stuff that GM mis-matched, starting with the '78 Cutlass that they were putting Chevy small blocks in them. That got GM sued in a class action suit by a bunch of new Cutlass owners. After that GM put a disclaimer on new car window stickers that some engines "are manufactured by other GM divisions". After that the floodgates opened. Some of the wacky FACTORY combo's I've seen: a '79 Olds Delta 88 with a Pontiac 301, lots of Chevy powered Oldsmobiles, lots of Chevy powered Pontiacs, Cadillacs with Buick 350's, Cadillacs with 307 Olds (my '89 Fleetwood came like this), some cars had Chevy straight six's while others had Buick V-6's.
As far as the Olds powered cars, depending on what body they were put in, a lot of them were designed off-set. I have owned over the last 40 years, three different Gm cars that came factory with the Olds 350 Diesel. Believe it or not, between 78-84, you could order the Olds diesel in almost every GM car, including the full size G-van and the C-10 pick-ups (before Chevy came out with their own 6.2 diesel). The diesels had a specific cast iron spacer plate between the motor mount and the block for the driver's side motor mount (it was about one inch thick) which moved the motor over toward the passenger side. I don't know if this same spacer was used on the 403 T/A's. Hope this explains some of what we're talking about. Your project sounds interesting, just like the Buick GS powered T/A's I've seen. I had at one point, back when I bought my first T/A, seeing if a Cadillac Eldorado 500 cu. in. would fit. Sounds crazy, but there was a speed shop in California that made motor mount adapters to put a 500 in any body GM car ! The 500 in stock form, put out over 400 HP and almost 600 lbs of torque !! This speed shop also would adapt the aluminum Edelbrock intake for the 429 Ford to fit it too, believe it or not the Caddy and Ford intakes are nearly identical, they just milled the bolt holes at a different angle, the gasket kits were the same.

 

[Munkyslut]

Yep, the advice from me is, don't swap in a 455 Olds. One of the worst swaps you can do for a second gen Firebird as there are so many better options you can choose. Like you have mentioned, you're going to have a lot of fitment issues and you'll come to find none of the accessories and most aftermarket parts will not help you at all.
The factory 403 Olds mounts are the same as many others and will still fit to the block fine, but the block is still substantially taller than the small-block 403 Olds so it's not just taller, it's even more offset and not centred with the Firebird hood ridge. They are a couple of dollars new on RockAuto, they are very cheap and common. There is not point getting used mounts when new ones are very cheap. The mounts are already very short, there's very little fat you can trim off them to lower them further.

Even if you graft on that aftermarket cowl hood thing, the 455 Olds will sit in a weird way where if you were looking down the center of the carb, it would be further off to the right, and that's with a standard cast iron manifold. It might not be enough to fully cover it. Keep in mind as well, the TH400 is larger than the TH350, and will also sit differently in the transmission tunnel, and might give you even more clearance issues with the HVAC box and exhaust.

I had a 1979 Firebird Esprit that was originally a 305 2bbl that had an Olds 455 swapped in it, fitment was abysmal, ended up parting the car out.

Excellent point raised about the difference in dimensions of the 400 & 350 transmissions
As the 403 powered cars (like my 10th Ann) only used TH350’s the use of a TH400 could cause engine mount/ bracket alignment issues.
I’d be measuring the trans, engine block & all accessories for overall (installed) length.

 

[theplummer]

Excellent point raised about the difference in dimensions of the 400 & 350 transmissions
As the 403 powered cars (like my 10th Ann) only used TH350’s the use of a TH400 could cause engine mount/ bracket alignment issues.
I’d be measuring the trans, engine block & all accessories for overall (installed) length.

I don't think this car even has a turbo 350, I think it has the 200, which is junk, so... Since the Turbo 400 came with the engine I'll probably try it, but yeah, a 350 can be made as strong as a 400, plus they don't rob as much horsepower as the 400.

The whole goal here is a fast, high revving big inch motor. Putting a big torque converter will be working against that goal... But the boy can't drive a stick shift, so that's out of the question.

 

[theplummer]

I've got updates...
Man, building a Olds is about as expensive as building a Ford.. I'm a Chevy BBC guy., where horsepower is cheap...
By the time the heads are done, we're beating the hell out of $5K and still only getting 340 cfm at .700 lift.. A set of 781's and a mild port job will easily get 320 cfm at .550 lift.. IMHO...
The problem with the Olds is the architecture. Particularly the hard turn on the short side radius on the intake side of the head... But, I think I've got the right CNC guy for the job.. He's really giving me some good advice, and knows how to explain the 'why' do it this way.. like 4 bolt splayed main caps. They are fantastic on a BBC for strengthening the mains.. However, on an olds, you find the weak spot between the main web in the block and the cam bearing journal.. His advice is to 1/2 fill the block with 'hard block' just to the bottom of the 'freeze plugs'... He says this will prevent the web casting from moving too much and the 4 bolt splayed mains can do their job properly.

Now, the engine builder.. I see why he's insisting on Jesel shaft mount rockers, but damn... $2K just for rockers? I'm going to have an easy $6K just in heads....

Oh well.. Like a very good machinist friend (RIP) used to say, "Quality remains, long after price is forgotten".

I think this is going to be expensive to do, just because of the architecture, but.. It's gonna be bad ass!!!

 

[chuckitall]

Interesting notes about the Olds motors. As far as strengthening the lower ends, I saw an article in either Car Craft or Hot Rod (probably 20 years ago) about a cradle developed for Olds blocks. The design of the cradle was the same concept of the Olds Arora/Cadillac Northstar V8. The maincaps of these engines are actually one-piece, where all 5 main caps are cast and align honed as one. Not sure how to explain it, guess the best way is to look at a GM service manual in the engine rebuild section. I rebuilt an Olds Arora at the dealer, back in the day, and the engine requires two oil pan gaskets, one for the cradle and one for the pan. Can't remember who was making the cradle for the old Olds motors, Mondello maybe?? The article was written to showcase that the Olds motor could be built to rev up to something outrageous, like 8500 RPM. I have the article somewhere, buried in thousands of pages of literature I have. Not sure if it's one of the articles Hot Rod has put out that can be accessed online.

 

[chuckitall]

Here's the aftermarket cradle for the older Olds engines.

PRW 0940311 Oldsmobile 350-403, Billet Steel Main Cap Girdle, Zinc Oxide, kit

PRW Billet Steel Main Girdles are engineered to help eliminate theblock flex andcap walk that occurs as a result of stress while under extreme loads, or du

poormanmotorsports.com

 

[chuckitall]

Here is a version that ties all 5 caps together, as the PRW only bolts to the front 4.

DMR-22361 Main 5 Cap Girdle - Dick Miller Racing

halo girdle will stabilize main caps 1 through 5 to help prevent main cap walk (flex)

dickmillerracing.com

 

[chuckitall]

As an interesting side note, one of my posts above where I mentioned the idea of stuffing a 500 cu. in. Cadillac in a smaller GM car, Dick Miller Racing also has built one that hits 650lbs and 550 HP on a dyno. They even make aluminum heads for them too !

541ci Big Block Cadillac V8 - Torque Monster! - Engine Buildup - Hot Rod Magazine

Check out Dick Miller Racings 541 Big Block Cadillac V8 with Total Seal piston rings, Check out this engine featured in the April 2008 issue of Hot Rod Magazine or at hotrod.com.

www.hotrod.com

 

[theplummer]

Here is a version that ties all 5 caps together, as the PRW only bolts to the front 4.

DMR-22361 Main 5 Cap Girdle - Dick Miller Racing

halo girdle will stabilize main caps 1 through 5 to help prevent main cap walk (flex)

dickmillerracing.com

Thanks for the research.

I specifically asked Performance Driven Design (CNC Head Porter) about the above Halo.

He responded that if I hard-block the bottom end and 4-bolt-splayed mains, the Halo is unnecessary.

But again, thank you.

 

[theplummer]

Update:
Heads, CNC porting (Precision Driven Design), Jesel Shaft Rockers, & 4 bolt Splayed Main caps are paid for.
Now they just have to 'do the work'. Jesel has to even manufacture the shaft rockers.

What I'm saying is, they are calling for a 4-6 week lead time on completion of this part of the build, so I may go dark for a while.
This is the beginning of racing season, so Salter is completely swamped with keeping his current customers satisfied, and this project will be 'fill in' work until all the parts are gathered up. I still have about a months wait on the Eagle 1/4" stroker crank for this engine anyway.
If he has time, between now and then.
Buckle up! This is going to be a ride? I hope.
Meanwhile, maybe I ought to buy a T shirt from Cleetus McFarland... I might just get lucky and win a free turbo... Umm, did I just type that?