Bart, there is a 236 cubic inch GMC engine with a 3 5/8" bore size. Your 228 block can be opened up to that size by boring the cylinders 1/16" oversize if it turns out the cylinders are worn tapered to the point of needing a rebore. That's roughly the equivalent of an .060" overbore to the 228 cylinder size of 3 9/16". That's a way of getting slightly more displacement without losing the original engine serial number, and the GMC block can handle a 60 over bore size with no problems at all.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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