Aluminum Block-heads

[RacerX11]

Racer, that would be naturally aspirated? (1 5/8").

Yes. I used 1-5/8" primaries on mine and they work great. The Power Manual recommends this size.

Marty

[fancyboy]

betterthanyou, thanks for clearing that up.

Racer, I keep seeing a "Power Manual" referenced here and there, is this something GM published?--where can I find one? (couldnt find it on the net).
I would like to take a look at their graphs/power bands..I do not want give up anything on the low to mid.
I used to run a big block chevy with the big square port heads, and 1 7/8" primaries are considered generous.


Thanks to ALL for the input, I valued all of your opinions/info.

[sharkey]

im building headers for mine. im going 1 1/2" primary and 2 1/4" collector 1 5/8 is a little on the big side for even a pretty modded 660. you have to remember that our motors are pretty small size for a v6.

its better to go way to small with primaries than a little to big.

[fancyboy]

Thanks Sharkey. I read about what you were doing in one of your previous posts (archives).

I am interested in purchasing one of those "Power Manuals"..if its even purchasable.