97 lt1 head casting numbers?
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Joined: Oct 2006
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97 lt1 head casting numbers?
What is the difference in the 643, 374, and 561 lt1 head castings?
I was planning on doing either an AI 190 or LE2 heads and cam package, but AI wants the 643 or 374 castings for that set up (LE does not specify on his site). I have an lt1 out of a 97Z with the 561's. What years had what heads and what is the best performance that I can get out of the 97 head?
I was planning on doing either an AI 190 or LE2 heads and cam package, but AI wants the 643 or 374 castings for that set up (LE does not specify on his site). I have an lt1 out of a 97Z with the 561's. What years had what heads and what is the best performance that I can get out of the 97 head?
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Joined: Dec 1999
Posts: 3,853
From: Jupiter (NPB), Fl
the 643 and 374 castings have more room for porting....
I'm not sure what the max that can be done is with the 561's tho.
You can find 374's and 643's on 93-95 cars.. I think some 96's had either 643's or 561's tho.
I'm not sure what the max that can be done is with the 561's tho.
You can find 374's and 643's on 93-95 cars.. I think some 96's had either 643's or 561's tho.
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Brandon Wittmer
General 1967-2002 F-Body Tech
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Dec 7, 2014 12:15 PM