Join Date: Jan 2000
Location: San Diego, CA
Thanked 0 Times in 0 Posts
Re: A few engine questions
If you got the cash I'd go with alum heads. The OEM 400 are the same type and quality as the 350 heads, just a different casting #. I had a set off a 350 and a 400, the # were different, but they were from the same exact mold. All the casting flaws and marks everywhere were exactly the same, just the # was different. Chevy made a bunch of different heads, only one or two were factory on the 400. They flow well, but are open chamber 76cc. As a general rule look for closed chamber 64cc heads. I have a book I got from Summit racing that says what # head was offered on what motor, it's a big help at the junkyard. Plus there is a book on "How to modify Chevrolet heads" by David Vizard, Amazon.com carries that one. They also have "Camshafts & Valvetrains" and "Blocks, cranks, pistons, rods". These are super helpful books. They also give a list of head & block casting #'s to use and stay away from. These books are a gold mine of info.
As for the SR heads, they are supposed to flow as good as the old OEM Hi-Po, but I think the Vortec is better. I have Air Flow Research alum heads and I wouldn't trade them for anything. Except for some overhead cam 4 valve heads, Oh sorry, I was daydreaming.
I would think of the block, crank, and heads as seperate componants. Pick the ones you want the most and put them together.
P.S. I'd stay away from PAW if I were you. Summit and Speedway are where I do my business.