Mailbag: How to Get 400+HP from a Pontiac 400 Engine
(Image/Street Tech Magazine)
You’ve got questions, we’ve got answers. We work with the Summit Racing tech department to help you tackle your auto-related conundrums. In this week’s Mailbag, we’re recommending a parts combo to get 400+ horsepower from a Pontiac 400 engine in a 1968 Firebird.
Q: I want to build a Pontiac 400 engine for my 1968 Firebird. What parts would I need to build a sweet-running engine that makes around 400 horsepower? (Money is no issue!)
A: We think the Edelbrock Performer RPM package would be ideal for you. Here are the parts you’ll need:
- Edelbrock Performer intake manifold
- Edelbrock Performer cam and lifter set
- Edelbrock Performer aluminum cylinder heads
- Edelbrock Performer head bolt kit
- Edelbrock Performer 750 cfm carburetor
The Edelbrock cylinder heads have Ram Air exhaust IV ports—so you should use this set of Hedman headers. Keep your compression ratio at about 9.5:1.
According to Edelbrock, this combo will yield 422 horsepower and 441 foot-pounds of torque on pump gas.
You mid-read the catalog!!! There’s no way the Performer cam will get anywhere near 400 hp. Barely mid 300’s is more likely.
The Performer intake must be run with a 1” spacer to out perform a pre 1972 factory iron intake! The Performer RPM would be the recommendation.
I realize the tech guys try to sell certain products but outside the heads and intake Edelbrock leaves a lot on the table with their generic cams and carburetors.
Dyno proven 405-419 hp @5400 rpm 470 TQ @4100 rpm.
400 9.50-9.70-1 Compression (Iron D-port heads)
Crower #60916 Cam w/1.65 rockers
Edelbrock RPM intake
Holley 750 carb jetted 74/84
This combo idles strong at 900 rpm and pulls 15# of vacuum. Shifts around 5500-5700
Add in a set of Edelbrock heads your well over 405-419 hp and can pull 6000 rpm.
Jeff Dubray – Do you have direct links to these parts by chance? I would like to look into this build set-up you have listed! Thanks.
Hey Jeremy, let me try my best to get you a more precise parts list. Though the details weren’t 100% clear on Jeff’s exact setup, these links may get you a little closer. We recommend giving the Summit Racing folks a call for precise technical recommendations: 1-800-230-3030
You can click these links for more info.
Crower Cam P/N 60916
Edelbrock Performer RPM Intake Manifold for Pontiac 400
Edelbrock Performer & Performer RPM Cylinder Heads for Pontiac 400
Holley 750 CFM Carburetors
Do you work for C & C?