I’m converting a 66 442, 400ci engine from an automatic to a four speed. The machine shop had the back of the crank drilled to accept a pilot bushing (bronze not a sealed roller bearing). This was before I found out that there is a conversion bearing that does the same thing w/o drilling. They also couldn’t find the correct bushing. I had to source it.
Depth of the drilling is .495 deep. Thickness of the bushing is.358. Is this o k to use? I’m assuming as long as it is flush on the face, it doesn’t have to go all the way in to the .495 depth..
The o.d. Is 1.382”. I tried to install the bushing but it was not going to go in easy…didn’t want to force it. May have to take something off the bushing or enlarge the bore. Either way it won’t take much…..0.001-2 maybe.
The I.d.is .0.582 which fits the M20 shaft perfect…not tight, but just a smooth spin.

Does anyone have any thoughts/experience with on this?

Tom

 

They are supposed to be a tight fit, to keep them from spinning or falling out.

 

That does not sound like the correct bushing. Are you sure you are looking at the correct part where he machined it ? The correct bushing is 1.094 od and about .750 deep. The one you have actually sounds like the conversion bushing ?? Can you post a picture of the back of the crank ?

 

Here are two pics of the back of the crank……..

 

Ok,
I guess I am wrong. I found my drawing and the pilot bearing hole is indeed 1.380 It should be a fairly tight fit though. Here is the post on this site from a while back:
https://classicoldsmobile.com/forums...ushing-163381/

What is strange is most of my books are calling for the same part number bushing as Chevy.

 

There are 2 sizes of bushings, and they went big. Probably need this one:
https://www.summitracing.com/parts/mcl-8-1380-1

 

The guy drilling the crank should have had the bearing or bushing in hand... either one will work. Crank looks to be drilled properly.

 

try freezing the bearing first ??

 

Before finalizing the bushing installation, measure the trans, bellhousing depth, etc. to make sure the trans input is fully engaged in the bushing when it is in the crank.