Does anyone have any flow numbers for stock 97-98 LS1 heads. I bought a set of 98 CNC ported heads and was wondering what the gains in flow are. Hoping someone has some before and after numbers. Any help is appreciated. Thanks.

 

i don't know the numbers,but they are real close to any other year..once ported,they'll flow just as well as any other year head..

 

Anyone else?
I was hoping to find someone who had before and after numbers.

 

stock are 222cfm, not sure how much your ported one's are but I would guess 280s for a stage 2 98 heads, maybe a bit optimistic.

 

I think it must be a stage 1 port job. The intake flowed 242 @ .500 lift with 28" H2O. The exhaust seemed quite good at 204. These numbers dont match the stage II PRC or the Patriot cnc ported 243 Z06 heads. This was a trade off for not having to buy new valve covers and coil mounts as these are perimter bolt. Thanks for the help.