383 vs 440
 

Helping a friend out and we are torn at what will be better for him. We've both always heard the old stories of the underdog 383 walking on the 440 4v "back in the day". So I've read that any given cylinder head can support X amount of hp regardless of engine size. So what we want to accomplish is a 66 coronet back half car that is done old school Superstock for our local series. My question is that given the 383 or 440 both have the same induction (ported factory iron, no fancy stuff) and relatively close compression, how much hp would he be giving up with 383? There's a 5 tenth difference in index here!

Re: 383 vs 440
 

Sorry there woul actually be a 6 tenth index difference because we'd have to claim GT/EA (10.95) with 440, versus SS/KA (11.55) with 383.

Re: 383 vs 440
 

The GT/EA will need a full cage. The 383 is probably a little better combo but it has to live at a much higher rpm and cam and convertor are more difficult to get right due to the short stroke and lack of VTP clearance. A 70 383 in GT/HA would be the most practical combo IMO, you will then have the larger exhaust valve and a choice of the Holley or the AVS as opposed to the small 66 AFB.

Re: 383 vs 440
 

We have run 10.90 @ D/SA wt. with 70 model 440 /375 with iron intake, AVS, and .450'' lift hyd. in the cuda.

Re: 383 vs 440
 

Does your series follow the Stock/Super Stock rules like the NHRA? I only ask because the 440 was not offered in 1966 but the 383 was.

JimR

Re: 383 vs 440
 

We follow the standard nhra/ihra rules. Using nhra hp factors and ihra indexes. The car has to be natural GT/EA (10.95) with 440 or SS/KA (11.55) with 383. And again I'm talking basically a stocker 3 ring bottom end with a solid cam and ported heads old school. This guy is chomping at the bit to get into s/ss but no way tossing 20k plus into an engine for his first real race car.

Larry we're looking at the 375 67 440 with the 9755 afb (750). Seems like the best balance of compression/induction for 440. Just that being a chevy guy those heads seem awful small for a 440+ cube engine

Re: 383 vs 440
 

You just said it, same basic heads on 383!