x heads ona 318

dodgetkboy78 said
Most between the later 973 heads, and the 302 heads, run around 70cc..... My 302 heads on my truck were 61-66cc from chamber to chamber....

Been a long time, but I think I remember my 894 heads being around 68-71.

Of course, when building something for power, all my chambers end up being the same size as the largest chamber in all 8.... Just logic, right?

So, really, IMO, your not losing much compression going from a mid 70's 318, to a 894 head, because the later 318's were made to have lower comression, and the 894 head was made for a high compression engine.

eh??

Only drawback for the big port heads, is the loss of torque, and it's pretty noticeable when running in a heavier car, or low stall tc/high gear ratio type deal.

I still say run it!!!!!

Not positive but I think the 894's stopped in 70 then it was on to the 915's. Seems the information is sketchy at best. No biggie though as they are nearly identical heads anyway (valve size considered).

I have never cc'd any 318 heads. Just always took everybodies word that the chambers are smaller so you loose compression going to 360 heads. You shed new light on the subject with your findings. Back in my early days of wrenching I knew nothing about different chamber sizes and replaced the heads on a buddies 78 318 with some heads (587's I think) off my old 360 and it ran much better. Take off was about the same but top end was a ton better. This was in a short bed pickup so it wasn't super heavy.