3999241 bbc head casting
Race Director
Joined: Jul 2015
Posts: 13,082
Likes: 3,399
From: SW Florida.
What do you want for the car to do? Powerful car that looks and sounds like it has a big block in it? These heads and the 396 are just fine. You want to try to break the 12-second barrier and get into the 11's? The 396 won't do it and neither will the heads. Also, it depends on the condition they're in. None of these heads are worth spending eight or nine hundred bucks doing guides and seats and new valves and Springs. And magnafluxing them because they're 45 years old. But if the guides are good enough to run and the seats and valves are good enough to lap and reseat, put new springs on them and run them.
Last edited by derekderek; Nov 3, 2018 at 06:49 PM.
Race Director
Joined: Mar 2018
Posts: 10,600
Likes: 2,064
From: Golden Colorado
1972 402 240hp,300hp,330 hp,LS3
454 open 365 hp LS5 113.0 cc
Not a bad head as far as BBC oval ports go, there are better and there are worse. The most questionable thing about this head is the combustion chamber was opened up around the quench area which does not help mixture during combustion, but is somewhat offset by the smaller volume which boosts compression. I have run them on street engines with good results. They are not worth doing a lot of work to if needed, however if in decent condition a lot of extra power can be found with a bit of bowl blending and port matching, if you do it yourself, again not worth paying for. If they need guides or extensive work not worth the money. Hope that helps.
454 open 365 hp LS5 113.0 cc
Not a bad head as far as BBC oval ports go, there are better and there are worse. The most questionable thing about this head is the combustion chamber was opened up around the quench area which does not help mixture during combustion, but is somewhat offset by the smaller volume which boosts compression. I have run them on street engines with good results. They are not worth doing a lot of work to if needed, however if in decent condition a lot of extra power can be found with a bit of bowl blending and port matching, if you do it yourself, again not worth paying for. If they need guides or extensive work not worth the money. Hope that helps.
Thread Starter
Instructor
Joined: Dec 2017
Posts: 239
Likes: 17
I should of been a little clearer in my expectations of the end result. These heads are on my 402 I’m putting in my 70 k20. I’m not doing anything too crazy here as this will be my daily driver. My 496 has afr 290’s full Cnc head that is going in my 70 c3 with a Straub solid roller and full forge rotating assy 11:1 compression, rpm Airgap with pro systems little monster carb and 3500 stall....I want to stay as sane as possible on this build and just make it reliable lol
