I realize it's 2022, and the article below was written in 2017; I have some essential information for anybody who owns an SD-455 and uses the original carb.
If you look at the 7th image in this article on the right side of the carburetor secondary butterfly shaft, there is a tab on the back of the lever.
On my super duty with an original carburetor, this tab hit the rod at the wide-open throttle, and the vacuum secondaries would only open about 30% of the way.
I removed this tab, and it produced an incredible difference.
After rejetting and reworking the timing, I ran in the high 12s, and I think the left front tire came off the ground.
If you have questions, hit me up.
I've had my super duty since 1999; it's in its second car and has about 30,000 miles.
https://www.motortrend.com/features/pontiac-trans-sd-455-pontiac-save-best-muscle-car-last/
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If you look at the 7th image in this article on the right side of the carburetor secondary butterfly shaft, there is a tab on the back of the lever.
On my super duty with an original carburetor, this tab hit the rod at the wide-open throttle, and the vacuum secondaries would only open about 30% of the way.
I removed this tab, and it produced an incredible difference.
After rejetting and reworking the timing, I ran in the high 12s, and I think the left front tire came off the ground.
If you have questions, hit me up.
I've had my super duty since 1999; it's in its second car and has about 30,000 miles.
https://www.motortrend.com/features/pontiac-trans-sd-455-pontiac-save-best-muscle-car-last/
Get Outlook for Android
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