I’m trying to find which pilot bushing ppl are using when doing their T56 swaps behind an SBC. The hole is quite a bit larger than I realized so GM pn 10252375 doesn’t work. What little information I have seems to indicate I may need an extended bushing as well. The crank is an aftermarket Scat 1pc rms piece if that makes a difference from stock GM cranks.

 

It depends on what engine you're putting it behind and which T56 it is

 

I’ve already made mention that I had an SBC with 1pc rms and I’m only aware of one T56 that fits that engine...

 

There's only 1 pilot bushing size for Chevrolet small block, that I know of. (well, apart from certain 1950s ones that came w cast-iron Powerglide; but that's not likely an issue here)

Exactly what size IS the hole in the crank? What did Scat say about it when you contacted them?

The "extended" bushing might be an issue for you though, depending on exactly which T-56 you have, out of the several variations that fit that engine.

 

Scat hasn’t been open since i found the confusion and the internet has provided no answers. Compared to the stock 305 crank and without a mic I can say the bores are the same but there are 2 bores, one just over an inch and the other just under 2. What I’ve seen of the SBC 1 pilot it may supposed to fit the large bore at 1.90” but of the 3 T56 LT1 cars I’ve put a pilot bushing in they’ve all used the minor bore. It’s an LT1 car T56, most likely a ‘96 Camaro SS judging by the factory Hurst shifter and shift **** attacked to it but I have no way of actually knowing. But then I’m also completely unaware of any differences between any 94-97 T56 other than gear ratios which would have absolutely zero effect on what pilot bushing I should be using.

 

All Chevy V8s since around 1960 have the same bores there.

Note that there are 2 "pilots"; one for auto trans that's about 2" or maybe a bit bigger, one deeper in that's for manual, at a shade under 1".



Here's what a crank with a bearing for a manual trans installed in it looks like.

 

OK, I missed the SBC, but there are 3 T56's and several combinations of trans and bellhousing. Your mention of the extended pilot is why I have no idea which T56 you're planning on using

 

Alright so I’ll go with an LT1 style bushing and hope for the best.