1972 Trans Am 455 HO Engine Build Photos

[TOG]

1971 455 HO engine build photos and specs
McInnis Automotive, Acton MA
.030 overbore, 462 Cubic Inch
455 HO heads, intake, and exhaust manifolds
455 HO 4-bolt mains
10.5:1 forged TRW pistons
455 SD forged rods, bolts, and nuts
Balanced pistons, rods, crank, and rotating assy
ARP head studs
Canton 8 quart baffled road-race pan
True roller double-timing chain
Ultradyne 3/4 degreed cam
1970s period correct M/T Pontiac valve covers
The gentleman holding the Canton pan is Bruce McInnis, the shop owner

 

[Pontiac Trans Am]

Very nice!

Thank you,
PTA Staff

 

[1911a1]

Awesome engine.

Like to period MT valve covers for the cherry on top.

 

[TOG]

The above engine build was completed in April 1988.

The 10.5:1 forged TRW pistons replaced 12:1 TRW pistons from a 1986 build done by the same show that was just too extreme.

As of November 24, 2022, this build only has ~30k miles on it and remains in my '73 Fire Am.

The carb and intake have been updated with an Edelbrock Performer RPM high-rise and Holly HP Street carb.

The rear main seal was replaced with a Butler Performance Viton seal, and ARP main studs were installed simultaneously, along with new oil pan gaskets and Butler Performance pan gasket reinforcements.

Last winter, the RA-IV/HO heads were freshened with new valve stem seals and a new 3-angle valve job and reinstalled with new ARP head studs and Felpro gaskets.

The period correct M/T valve covers in the 1988 vintage photos are embossed "PONTIAC" on the underside and were donated back in the day courtesy of my then Tri-Power 4-speed Hurst Competition Plus-shifted '65 GTO, long gone but most certainly not forgotten.

The Hurst "T" shifter handle and the dome light with dual map lights from my '65 Goat also live on in the '73 Fire Am.

Photos below are as of Nov 2022; the '65 GTO photo was taken in 1975, before the donations to the Bird.