I've read a few different oppinions on wether or not factory castings will flow enough to feed a 383. I'm doin a rebuild and it will have max port heads but will that be enough? Or would I be better off just goin 355?

 

Depends on what you plan to build. if it's a high rpm (7,000rpm+) screamer then stick with the stock stroke. for anything else, go for the cubes.

Rich

 

I would like to at least pull 62 -6300 rpm.

 

High rpm in this context is approaching and above 7K. 6,200-6, 300 should not be a problem with ported stock castings.

Rich

 

u wouldn't want more cubes if you rev higher? doing a 355 and plan on shifting around 6700-6900. just make sure i understood what u meant.

 

OEM castings will have a tough time flowing enough to support big cubes/high rpm. A 383 at 7,000rpm needs too much air. It would require thousands of dollars of port work if you start with stock castings. Closer to 6,000rpm though and you can have a nice combo with lots of low end torque that pulls strong up to 6,200-6,300.

Rich

 

I agree with you stay on the low side of 6500 rpm the stock castings with biggervalves and nice porting. My AFR 190s just cleaned up make power past 6500, I was kinda surprised. I plan on having them worked over good this coming winter so I'm anxious to see how they do.

 

My 306 cam will still work fine in a 383 shifting around 6200 right? or will it try to make power to high up in the rpm range?

 

You'll be fine with the 306, but it will want to shift probably just below 6500.

I have the GM 847 in my 383 , 10.3:1 compression and it will rev to 7000 with ease, but the power starts to drop shortly after 6500

 

Agree. The drop off is what you would expect. The heads (and intake) are the limiting factor.

Rich