Chicago94Z28

How many different heads did GM make for the LT1? And what were the head cc's if anyone knows? Also flow #'s if ya don't mind?

thanks.
Tom

Blue89Bird

as far as I know 3
LT1 heads came in aluminum and cast as well
as well as the lt4 heads.

Chicago94Z28

I guess I should be more specific. I was told that the 94 25th anniversary trans am heads have a lower chamber volume. 54.4 cc's versus the standard 58 cc's of a regular lt1. Did any lt1's come with this chamber volume? I know the lt4's did.

Blue89Bird

sounds like a load of BS to me.

Chicago94Z28

Well I am thinking of buying them and we will see. Maybe I misunderstood him but he claims they are 54.4 cc's and I will call him on it if it is B.S. He lives close to me so I am not very worried about it. But if they are higher compression I will gladly accept them. Any little advantage helps. Tom

Dr.Mudge

Maybe he had them shaved.

rskrause

It's misinformation at best, or possibly just BS. So what anyway? You can have a set of LT1 castings milled if you want a smaller CC. Why does it matter, what do you have in mind?

Rich Krause

GUMP

Tom,

Aluminum LT1 heads.

10205245, 10128374, 10207643, 10207640, 12551561.

As far as I know the only head that is different is the 561 (lighter casting). I have them on my latest LT1 and have had very little gain with them so far.

I mill all of my heads to about 52.5 cc's (NHRA minimum is 51.9).

The cast iron LT1 head is 14088526 (62.0 minimum).

The LT4 head is 12555690 (54.4).

Best Regards,

Daren

Chicago94Z28

Ok I am also looking at a set of steel or cast iron lt1 heads. The only numbers they have shown are 25320. Is this an lt1 head?

So if these are high cc heads I can just have them milled to like 53 or 52 cc's. Will I run into piston to valve clearance issues then?
Thanks for all the help guys.

here is a link to the low cc heads:

http://cgi.ebay.com/ebaymotors/ws/eB...411459826&rd=1

arnie

Aaaaannnnnd, the LT1 head cc. at 54.0 (blueprint spec) What that means is the LT1 head, in production, will have anywhere (realistically) from 56-58 cc. IOW, if you take a head off an engine and cc it, don't expect 54.0 cc., but something like noted above.

SVT Killer LV

4 Castings
---------------------------
2 LT1 Alluminum Castings
1 LT4 Alluminum Casting
1 LT1 Iron Casting