Ford TopLoader for a bigblock behind a small block

[rhart]

Hi all,

First thanks to all you fellow Cobra guys that use these forums. The discussions here have help me out time and again.

I purchased a 351W with a Ford Top Loader attached to it that I put in my Cobra. I ran it for about a year now.

I have started to replace the Clutch, Pressure Plate and TOB. While replacing all this I found that the "stock" Pilot Bushing was shorter that the one I pulled out by about 1/8".

The tranny appears to be a Top Loader for a Ford Fairlane with a 390 engine(Tag #HEH CL 015155.) The bellhousing was changed to fit the small block but the input shaft nose is only 3/4".

I have read that this can possibly damage the tranny. What should I do in this situation?


Any info is appreciated,
Rick

[TerribleTed13]

With 1/8 inch difference, I'll think no big deal. But go to a parts house(Napa) and match up your old one. Better yet get a bearing instead of a bushing. The bushing/bearing just supports the imput shaft, at the crank end.

[David Kee]

Rick,
The tip of the input shaft needs to be 1 1/8" long behind a small block. If you run the shorter 390 input it will not reach into the bushing and cause front bearing failure in the transmission.

[rhart]

Hi David,

Would a longer pilot bushing be sufficient or is that inviting failure? I could have one made it this would take care of the problem.


Any information is appreciated.
Rick

[David Kee]

All of the extended pilot bushings I have seen have not lasted very long. They wallow out and then it is a disaster for the transmission.