can anyone tell me where i can find flow/dyno info on stock chevy exhaust manifolds, and possibly what vehicles to look on for the good ones???    
rule book says no turn back center dump rams

thanks  

I don't have any data on stock exhaust manifold flow. But when it comes to factory exhaust manifolds the generally agreed best model to use, if you're restricted from the "Rams Horn" style, is the 1988 thru 2002 truck 350 exhaust.

These are an under the spark plug design, but unlike those of similar design used in passenger cars, these have a larger cross section and have 2-1/2 inch outlets that depart at a 45 degree angle between cylinders 5 and 7 on the left and 4 and 6 on the right. They are also a heavier/stiffer casting which solves the passenger car manifold warpage problem that always ends up curling the end spigots so they will interfere with the flow out of 1&7s and 2&6s ports. Since your sanctioning body probably also frowns on grinding the manifold openings to match the ports these later truck parts do the job as well as it can be done with stock manifolds.

Bogie  

Thanks!

I have heard a little about the truck manifolds!, I'm off to pick a part!!!

cheers      

i know this post is old...

stevensparts.co -m has a page with images and primary applicatiopns... some intresting desings in cast iron also... 100 times more effective than trips to a junk yard... no flow data though.  the firebird over the top items look intresting...