Hi Guy's,

I need some help!! I just put a rebuilt 350 in my 71 cutlass supreme just to find out that the crankshaft is for an automatic and I have a manual transmission. I found out they have special tapered pilot crankshaft bearing that will convert a automatic crankshaft to a manual without drilling the crank. has anyone used or had any success with these bearings or do I have to tear the engine down and go get the crank machined? thanks for your help!!

 

Some on this site had good luck, most did not.. Here's one link there are more if you search...

https://classicoldsmobile.com/forums...t-bearing.html

 

SEARCH is your friend...

https://classicoldsmobile.com/forums...g-adapter.html

https://classicoldsmobile.com/forums...t-bearing.html

https://classicoldsmobile.com/forums...onversion.html

https://classicoldsmobile.com/forums...ter-issue.html

https://classicoldsmobile.com/forums...-question.html

https://classicoldsmobile.com/forums...t-bearing.html

https://classicoldsmobile.com/forums...t-bearing.html

 

This is jmo. It seems the comments from people who have done this, long term success is less than 50%. Pulling out the crankshaft and having it properly machined is 100%. Imo, trimming the "snout" of the main input shaft is always a bad idea. Hand drilling a recess in the crankshaft is also a bad idea, to many variables. There is also a chance the recess where the "sneaker" bearing goes may be off centered.
After all that, a few have had success. The 403s crankshaft "looks" like the best chance for success, to me, because of the 3 step down recesses depth "may" give the proper length plus clearance for the "uncut" main input snout. Last Wednesday I took 3 crankshafts, two 400/425s and one 455 to be machined for factory type pilot bearing. I'm getting to old to "gamble" on the "sneaker". All comments are jmo.
If you feel lucky and try the "sneaker" bearing please tell us your results.

 

Hey Kenny thanks for your reply. I think I'll just get the crank machined and have the BCA 7109 Ball bearing pressed. is there a schematic to give or show the machinist? what do I ask for when I take the crank and bearing down to the shop. thanks again for your help!

 

Here's an old thread that has the details on drilling out a crankshaft for the pilot bearing or bushing.

https://classicoldsmobile.com/forums...snap-ring.html

 

Check the links posted above, the diagram has been posted on the site many times..