[V8Vairs] Pilot bearings on engine swaps

Ed Dowds ed_dowds at hotmail.com
Fri Jun 16 08:11:17 EDT 2006

"There is also a reference by Steve Semon on the placement of the pilot
bushing,there is a possible problem with the bushing being too far out of 
the crank
and similarly if the bushing is too far into the crank then the input shaft 
room to move back and forth."

I used an MID engineering swap on my first Corvair, a rear V8 back in 1971.
I saved the kit and I'm now using it on a rear 4.3 V6 '66.
Originally the kit came with a standard pilot bushing and a second one cut 
in half. You installed the half bushing first and then the standard bushing 
to end up with 1 1/2 times a standard bushing. The kit used a shaft made 
from cutting off the Corvair splined end and welding on the end from a V8 
trans shaft. The shaft has the same dimensions as the "V8" shaft in Clark's 
catalog, I think it is 25 1/2".
Since I am now older (and more paranoid!) I decided to check things out 
before I installed the powertrain. I hooked the trans to the engine without 
a clutch and measured how much longer, than a standard one, the pilot 
bushing needed to be. I ended up using a bushing that was designed for 
engine swaps. It was available from Advance Auto but I have seen it in other 
The end that goes into the crank looks just like standard bushing. It is 
longer than a standard bushing and the part that sticks out past the crank 
has a larger diameter that looks like a flange. If you ask what the bushing 
is designed for you only get a blank stare from the counterman. I think 
there was some reference to it being used to put a standard trans behind a 
V8 that originally had a TurboGlide!  Since those were used in 1957 to 1958 
or so I think there isn't much call for them! I have seem catalogs listing a 
similar bushing for putting a Ford Flathead V8 behind a Chevy engine.

I had to space the bushing slightly away from the crank. I used a washer of 
the proper thickness and used Locktight to keep it in place behind the 
flange of the new bushing.
A new bushing could have been made from the proper material. The flange is 
made to register in the crank where the hub on the front of a torque 
converter would insert.


More information about the V8Vairs mailing list