317 heads vs aftermarket
06-09-2008, 07:02 AM
#1
317 heads vs aftermarket right now i have a 6.0 (lq4) with a z06 cam, stock 317 heads(w/new springs) forged rods/pistons, 9.2 comp, disc procharger, vic jr intake, bt carb(in a chevelle) i have not got the tune down perfect, but getting better-the biggest holdback is the rear, 3:31's with 28" tall tire-gonna swap in 3:55's, still not the best with the 2:48 first gear(switch/pitch turbo 400) i would really like a 4l65e, with the lower 1st gear, maybe later
anyway, i was looking at upgrading the cam/heads-pretty sure i know the cam specs i want, but the heads im not sure on-what is the flow on the 317 heads? AFR rec 225 heads (i need 72 cc) seem pretty large to me, based on my old gen 1/procharged setups, where i used 195's with good results
would switching to heads in the 220 range kill off a lot of low end(i know the cam will kill a little) i know the rear ratio is still gonna be a killer, but trying to keep it somewhat driveable on the road, w/o hearing it screamin, lol
i have an 850 carb, which i think is a little to big, but i had it in stock, left over from another project, and has good afr's
and yes, this winter may switch to FI(been collecting parts, ls6 intake, computer, wiring)
anyway, i was looking at upgrading the cam/heads-pretty sure i know the cam specs i want, but the heads im not sure on-what is the flow on the 317 heads? AFR rec 225 heads (i need 72 cc) seem pretty large to me, based on my old gen 1/procharged setups, where i used 195's with good results
would switching to heads in the 220 range kill off a lot of low end(i know the cam will kill a little) i know the rear ratio is still gonna be a killer, but trying to keep it somewhat driveable on the road, w/o hearing it screamin, lol
i have an 850 carb, which i think is a little to big, but i had it in stock, left over from another project, and has good afr's
and yes, this winter may switch to FI(been collecting parts, ls6 intake, computer, wiring)
06-09-2008, 07:20 PM
#2
The AFR heads are much thicker and will handle a lot more boost before popping a head gasket. The 225cc heads will work good with a 6.0L, I wouldn't worry about them killing off the bottom end. Check out my build. http://www.exoticperformanceplus.com...Car.php?car=12 Bob
06-09-2008, 08:08 PM
#3
The AFR heads are much thicker and will handle a lot more boost before popping a head gasket. The 225cc heads will work good with a 6.0L, I wouldn't worry about them killing off the bottom end. Check out my build. http://www.exoticperformanceplus.com...Car.php?car=12 Bob
