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Big bore head gasket differences?


Well-Known Member
Local time
10:44 PM
Jan 1, 2010
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Erda, UT
The block I am prepping to replace my cracked Original has HUGE chamfers. Some will come out with decking, but I will still need to use 4.590 bore head gaskets to keep the fire ring away form the edge.

496" @ 4.360, 10.4:1 compression, Ported Eddie RPM's, little over 600 HP.

Fel-Pro 1105's and 1039's appear to be identical except for the comment about a pre-flattened steel ring, and the obvious dual bolt pattern on the 1039.

What is the difference? I would go Cometic, but nothing is available in-stock on my time frame. I looked at the 8519-PT1's, but they are "only" 4.5" bore.
Mopar has an issue with: screwed up, oversize, and deep chamfers. I did a block for a guy that blamed me for screwing up his block. After he got it back, he pulled out the hand grinder, and when he was done, the gaskets I got him would not work anymore. Go with the Cometic gaskets, and the wait is not too long. I just ordered a set for a customer, and they arrived in 3 weeks.

They are the same, just that the 1039 can be modified to fit the Hemi.
I ordered the set I have on hand (4.410 bore) from Cometic, and it took 4. They said it would vary as parts are built in lots. RMRW 2.0 is a month from today. I need these in less than 2 weeks, which is when I get the block back.
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