In the middle of May a buddy of mine bought a Black Knight addition El Camino, which turned out to be a lemon, regardless he stroked the 350 to 383 and slapped on a pair of aluminum patriot heads. Now, i am not sure the model number however, i do know they are aluminum and 195cc intake runner. i was looking on the website and they offer heads with 225cc intake runners, so my question is what does the bigger intake runner give you? Pro's/Con's. What i can think of is more hp, maybe worse fuel economy and better or worse compression ratio. Thoughts on this?

heads have to match the intake/cam/engine displacement/driving habit/HP goal/power RPM range/wat the car will be used for/compression ratio... basically everything.

i have the patriot 195cc heads...i just put them on my 383... ive been told that i should be in the 480hp range. with my cam/heads/intake etc i matched my rear gears and converter stall and i should be making peak power like 5500 but i should be able to rev to 6000 with no issues and not losing much if any HP. engine/car specs are in my sig.

larger CC heads like the 225CC vs the 195cc will mean larger intake runners, u will lose low RPM hp/tq with larger heads.and u could make less overall power etc depending on intake and cam that your gona use. basically u need to match everything or your engine will be not as effecient as it should be. larger CC runners will increase RPM range as well as peak HP/Tq numbers... the 225cc heads will be too much for that 383 unless u match the cam/intake for it which will require a LARGE cam and HIGH rpm intake. car will prob rev to like 7000 and will useless on the street since u will need a 4000 rpm stall converter to get into the power band. not to mention little to no vacume at idle for power brakes etc, impossible street idle. u will need really steep rear gears too.. like 4.11 wouldnt be enough. prob like 4.56 etc

compression ratio is all on the combustion chamber size. u can get usually 58-64-72cc chambers on the same heads depending on the company. compression is also determined by Piston compression height/deck height/ piston Dish/dome size, head gasket thickness.