From what I have read the iorn L98's and the aluminum ones off of the vettes flow almost the same. Is this correct or am I mis-lead. If this is legit then would it be safe to say that a iron L98 head milled to 58cc's would give the same power gain as an aluminum one on a 305? Also I have read where people have said that they have gotten a 30 hp gain from doing an L98-aluminum swap on a relativly stock 305 (stock cam and intake just intake porting and bolt-ons). This seems extreme to me. I didn't think the 305 tpi heads (416's I think) were that restrictive.

 

If your car's an 87 you got 081 heads not 416's

 

They don't flow the same. They are close, probably within measurement variability, on the intake side but not on the exhaust side. See the details in this thread, approx 2/3 rds of the way down in my summary post. The source for each of the numbers is listed either as a clickable link or otherwise cited in text. Ported flow data are also listed, along with their sources. HTH.

 

Yea my cars an 87. Everywhere I read , I read that the 081's and the 416's are pretty much identical other then the 081's are centerbolt valve covers.