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Old 05-06-2026, 03:54 PM
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Join Date: Aug 2009
Location: Elgin
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Quote:
Originally Posted by hurryinhoosier62 View Post
How many times have you personally replaced the main cap on a block, then align bored it? Me? Couple of thousand times. There are ALWAYS fitment issues; that is why I kept around 150-200 main caps set for the most common blocks we machined. On average, I was able to match a replacement main cap after 8-10 tries. Keep in mind this was a cap that fit close enough to cut the cap( usually .006-.010) so the carbide of the align bore machine was taking the majority of the material out of the cap instead of the block. Then, you have to resize the rear main seal area to prevent fitment issues. Here is my advice to everyone opining here( with the except of Mike G): if you have never performed this operation on an engine block leave it to the professionals who perform these matching operations every day.

Hey good for you. I'm surprised your big head fit through the forum door.

In a perfect world, with motor out and at the machine shop, of course you would have the motor align-bored or align-honed depending on the severity of the misalignment of the replacement cap. The cost and effort is insignificant vs the potential for main bearing failure..

The OP is looking for an option short of pulling the motor out, disassembling and hauling it to the machine shop, but you obviously missed the drift because you know it all.

He is willing to risk the consequences of a short-lived rear main bearing if the "fast-pass" doesn't work out. The inspection procedure I suggested, removes as many variables as possible for a successful outcome in light of the circumstances and his desire to avoid a full teardown.

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