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In an attempt to plan to reduce my Buicks 3.250 main journal size to 2.750 I was thinking spacers/caps.....
Are these considered a solid idea?
Is there anywhere special to have them made?
 

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Gary,

What are the chances you can get the block mains sleeved? Something more permanent? And if 2.75 is good then 2.45 would be better? I'm know I'm pushing.

I've never taken the time to do so, but is it possible that you could use a 3.25 bearing AS the spacer? That is what Comp Cams sells as spacers. They are bearings, that have slots added for the tangs. It might be a little more complicated than that but again, I've never even looked into it.

Again, I envision some round stock cut, and fitted to the current main bore, fastened with countersunk screws, and then align honed to a specific bearing size.... like a 2.45. And for caps.... nothing special there just have some made of billet steel with a bore roughed in enough to align hone.
 

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In my Olds I used aluminum spacers in the upper and billet caps for the lowers. I went from 3" mains to 2.5" mains with this process. I had Bill Trovato from BTR Performance make the spacers for me. The uppers screw into the block, fit the caps, line hone back to spec and its better than new.......
 

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You are right Chris about the spacers. I was in a shop one time and the guy sub contracted from manley to make the spacers. They were just out of the box bearings, I think like .080 unders and they were adding the locating cut out with a "t" slot cutter and re-boxing them in the spacer box. So i think that is all that needed done to make them work.... I have never seen any issues from using the spacers....You might have a problem finding a bearing with that typ of wall thickness for your application....

I like the idea of a more permanent fix. But i am sure it's going to be costly to get it all fabbed up. I had a DZ302 block one time to fix that had the front main out. I started getting all my drawings to make a bolt in shell but it cleaned up by moving the centerline .010.... So i never finished the drawings or made the parts....

keith
 
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