boynton6spd

Corvette Brothers,
I just picked up a 1972 454 LS5 big block with 1968 427 "Closed Chamber" iron heads...
Can these heads 3917215 build power by todays standards?
My builder hates them and wants me to use something else...
I'm trying to keep this on a reasonable budget as I wasn't planning on doing a big block swap until this came up at a great price...
Any recommendations will be listened to intently! lol

trw

The heads are good. Some cleaning up and larger valves will make them better.
They are a plus for a flat topped short block. 100cc.
Depending on your goals and pocket book, they will work, there are better but $$$.
I am running them on my 450+hp engine.

Big Block Dave

Im going to go out on a limb and guess that your builder wants to put an open chamber rectangle port head on the motor.

IMO the 215 is a desirable casting, and I would run a set on my LS4 in a heartbeat. Years ago, I had a set on a 396 that went mid 12's in a 67 Chevelle.

Search chevelles.com for more info on closed chamber oval ports, and I suspect you will find a few people that have gone pretty fast with those heads.

blue427

if you put open chamber heads on you'll probably lose alot of compression,which means new pistons.There goes your budget.You probaly have closed chamber pistons in there now.Open chamber rech. heads and low compression will make for a slug of the line.Leave the heads and just do a little work on them as suggested in the other post.I didn't know they made closed chamber heads for a 454,G.M. went open chamber in mid 69(427)