Head casting number
Thread Starter
Racer
Joined: Aug 2011
Posts: 343
Likes: 10
Head casting number
I bought my 93 used. I recently pulled the valve covers and found that one has the casting number 643 and the other is 374. It sounds like that they are pretty much the same. Other than this throwing a red flag of some kind of problem in the past should I try to match them up or no big deal?
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
Team Owner
Joined: Sep 2003
Posts: 25,389
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I don't see either here?
http://www.mortec.com/castnum.htm
http://www.mortec.com/castnum.htm
OP - Your observation I'd guess is that they're very similar. The difference I'm not familiar with but OE the part number did change in '94 and the valves seem differently part numbered. I'd think if I could I'd prefer a pair of the same! If it's what you've got and it runs well then I doubt there's reason for concern.
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
I saw both a 643 reference and a 374 with the 374 reference likely an OE '93 and the 643 likely a reference for '94+.
OP - Your observation I'd guess is that they're very similar. The difference I'm not familiar with but OE the part number did change in '94 and the valves seem differently part numbered. I'd think if I could I'd prefer a pair of the same! If it's what you've got and it runs well then I doubt there's reason for concern.
OP - Your observation I'd guess is that they're very similar. The difference I'm not familiar with but OE the part number did change in '94 and the valves seem differently part numbered. I'd think if I could I'd prefer a pair of the same! If it's what you've got and it runs well then I doubt there's reason for concern.
Thread Starter
Racer
Joined: Aug 2011
Posts: 343
Likes: 10
Thanks guys. I had no issues with my heads. I just noticed the different casting numbers and threw the question out here in the forum just to confirm that everything was gtg.
