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rebuilding a 260, all if the kits come with 289/302 4 inch bore head gaskets. i have built a few 302s. my question is, how much compression will i lose using these oversized bore gaskets. it is a daily driver, so not looking for a hotrod.. or is it worth finding actual 260 head gaskets

Here's a good calculator to account for gasket hole & piston bore- https://www.gofastmath.com/compression- ... calculator

Joe

I don't think you will find 260 bore sized head gaskets. 4.030 is the smallest commonly sold bore sized head gaskets that I have seen. I am sure it will be fine with those. I used them on a 260 I ran years ago with no issues.

bmmaurer wrote: ↑

Mon Sep 26, 2022 9:14 am

https://www.rockauto.com/en/catalog/mer ... asket,5412

All of those are over 4" bore, not specifically for a 260

Ran the calculations between 4.10 gasket bore & 3.90 just for the heck of it.
Less than 0.1:1 difference. The combustion chamber tolerances varied more than that from the factory.
I don't see any available but I wonder if the steel shim gaskets are still available to raise compression? That was the ticket many years ago.

Joe

efmiller wrote: ↑

Sun Sep 25, 2022 10:34 am

rebuilding a 260, all if the kits come with 289/302 4 inch bore head gaskets. i have built a few 302s. my question is, how much compression will i lose using these oversized bore gaskets. it is a daily driver, so not looking for a hotrod.. or is it worth finding actual 260 head gaskets

You will see NO performance issues. Have used these twice. no issues

thanks guys. i will go with the standard kit. it will be going into my daughters 63 4 door.

Did you find a piston besides the Silv-O-Lite for the rebuild?

Joe