Pilot bushing clearance

I have read both here and on other sites that most if not all Buick cranks are drilled for a manual transmission. But I have also read that the clearance is not always what it needs to be and that sometimes you need to mill the bushing. My son and I are about to convert his 68 special deluxe to a stick shift. It is a 350 car. I can measure the crank and the bushing, but what is the right clearance between the two?

 

There are threads on this topic. Try "turn pilot bushing" in the search function.

 

I believe Jim Weise sells an almost-drilled-for-manual pilot bushing for Buicks. I believe it works when they didn't quite finish the hole to proper specs and left a taper at the bottom of the pilot hole.

AutoGear gives the B-O-P size for standard as:

Inside diameter: .592/.593
Outside diameter: 1.3782/1.3877
Length: 0.420

They also sell oversize and extended.

From this PDF on their site: http://www.autogear.net/wp-content/uploads/2015/03/pilot_bushing_chart.pdf

 

Having a 350 being built, assume it was from an automatic car. The hole was off centered in the crank after my machinist corrected it the pilot bushing was too loose so he’s making me a two custom ones so if I ever need a replacement I have one. He said he’s see a lot of cranks drilled off center from the factory over the years

 

Thanks for responding. I have read will the posts I can find, but didn't see what the clearance should be. Since there send to be done variations, I want to make sure I have the right clearance so that I don't have the bushing too loose.

 

If you give JW your crank’s diameter, he says that he can make one for $20 with the correct overage for a press fit.
https://www.v8buick.com/index.php?threads/crank-drilled-for-pilot.322353/#post-2690866

 

It is very important not to drive the pilot bushing into the crank, it will deform the inside diameter!
I found out the hard way when I couldn't get my it in any gear while the engine was running.
The transmission was still turning with the engine even when I depressed the clutch.
I had to turned the outside diameter of the pilot bushing to make it a snug fit into the crank so not to deform the inside diameter. It only took my three tries to get it right!