Heads on a 400? - Third Generation F-Body Message Boards

WinnipegGTA · 01-02-2003, 04:48 PM

Just wondering if any set of heads can be bolted up to a 400 block. Like Aluminum L98 heads or AFR 190/195s. I know about steam holes and such but to coolant passages and stuff all line up the same??

RB83L69 · 01-02-2003, 04:54 PM

Yes.

WinnipegGTA · 01-02-2003, 07:16 PM

Merci

ohyeahjay · 01-03-2003, 06:35 PM

if your running it on the street it is highly recommended to have steam holes drilled in them

camaro03 · 01-03-2003, 10:12 PM

my machine shop told me i had to have steam holes drilled in them for them to work on a 400, i could be wrong though

RB83L69 · 01-03-2003, 10:14 PM

They're not wrong. Drill the steam holes. It's 6 holes per head with a 3/16" drill bit using a 400 head gasket as a template. About 5 minutes work, taking it easy and counting beer breaks. Doesn't get much simpler than that.

Sitting Bull · 01-04-2003, 01:28 AM

Quote:

Originally posted by RB83L69
They're not wrong. Drill the steam holes. It's 6 holes per head with a 3/16" drill bit using a 400 head gasket as a template. About 5 minutes work, taking it easy and counting beer breaks. Doesn't get much simpler than that.

Yes, the latest Chevy High Performance mag has a how-to article on it.

F-BIRD'88 · 01-04-2003, 01:40 AM

The only small block head that you can't use on a 400 block are
the 350 LT-1 and LT-4 reverse cooling genII type of head.

There is no point in trying this as the Vortec and Fastburn head are fashioned after these and flow way better and are cheaper.

The LT-1 type EFI intake manifold can be adapted to the earlier
GENI head thou.