Quote:
Originally Posted by Young Pontiac Guy
Great responses, thanks to all.
My goals: fun street car that runs low 13/high 12s. Car is 4 speed Bird. Fine with reving to 6000rpm. Dont really want to drop the extra couple grand on doing a stroker, plainly. Plan on using my stock intake which is Felpro gasket matched and cleaned up, Qjet, etc. Car has a 2.56 rear gear currently but looking to remedy that over the winter as well with a 3.08/3.23 (dont have yet).
Would likely go with KRE 310 DPorts. They are close to me here in Ohio.
How would the car be from 2000rpm on up with a set up like this?
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We've built many 400 combo's over the years, we use to run a 413ci cast iron headed (265cfm) engine in our 3600lb 65 GTO which ran 10.20's @ 130mph. I love the 400 combo's but they are a bit more sensative to having the gearing (conv. if auto) matched correctly with the engine combo, not saying it isn't important with the 455 or stroker combo's but the bigger torque of the longer stroke can overcome a lack of conv. stall or rearend gear and still perform very well.
If your plan is to run 3.08-3.23 rearend gears along with a stock intake then I'd suggest a 290-295cfm max as the higher flowing head with it's larger port entrance won't match the OE intake vary well and the larger cross section will push the power curve higher in the rpm range which will be better complimented by a longer duration cam which won't work very well with the modest rear gear you plan to run.
Years ago we set up a customer with a 73 Formula, factory 4 speed and 3.42 gears, with a set of mildly ported 4X heads (225-230cfm) and a Summit 2801 cam. He bolted these on to a basic 406 shortblock which yielded 8.5 to 1 compression for 87 octane daily driver usage and for exhaust he had RA exh manifolds with 2.5" pipes. He used a stock intake with a Q-jet that he tuned and the car on regular street radial tires (read traction impaired) laid down 13.40's @ 105-106mph and he reported fuel ecomony in the mid teens as this car was used as a daily driver.
Here's a link to another one of our customers we built a 400 combo for
http://www.sdperformance.com/custome...01.php?carID=9 obviously he has a bunch more rear gear and a 5 speed trans but it gives you an idea what can be done with 290ish cfm cylinder head on a 400 combo.
You won't have a problem reaching your goals, just keep in mind bigger isn't always better when it comes to cams and heads. The stock intake with a bit of work is an excellent choice. Get in touch with Cliff Ruggles for some tuning parts for your Q-jet.
We got my 17 year old son Zac out to the track this year in a borrowed 67 Lemans (ran out of time to get our 65 Tempest together), we took a runner 400 shortblock with 40,000 original miles on it (never been apart since Pontiac put it together), Old Crower 224/228 112 lobe sep cam, bolted on a set of 250cfm cast iron heads (9 to 1 compression), prepped iron intake and a 750 Q-jet with a Cliff's tune up in it and the car ran 12.68 @ 106mph with a 3.73 rear gear and a 3500ish stall, leaving the car in drive (column shift) and no tach so it was short shifting big time.
What type of camshaft were you planning to run? (flat tappet or roller)
What is your plans for exhaust system?
Dave