zigroid

iTrader: (22)

my buddy has an LT1 and a t56 in his RX7. he is indecisive whether or not to upgrade to an LS1 . his main concern is he has a lot of money tied up in the current t56 and doesn't want to get rid of it nor does he want to deal with the hydraulic clutch of the LS1 t56s.

what kind of options are there for mating an LS1 engine to an LT1 t56?

Thanks.

thesource

iTrader: (60)

Swap the input shaft, mid plate and bellhousing as long as the LT1 unit is a 2.66 ratio transmission.

SlideRight

How does the ratio make a difference?

85MikeTPI

iTrader: (9)

The early M28/M29 (1993) T56s will have different countershafts,etc. so the MM6 inputshaft of the LS1 won't work with those.

If you do convert the LT1 T56 to the LS1, you will have to use the LS1 oem style HYD slave/TOB.. If you want to avoid that, you need to look into an adaptor bellhousing/flywheel that will allow you to run the LT1 external slave setup. (If such a bell/fly even exists?)

thesource

iTrader: (60)

What kind of clutch setup does he want to deal with? I know of a few options.

jmd

iTrader: (4)

Change to the LS_ input / front adapter plate
Use an aftermarket adapter plate w/brg retainer (to bolt LS_ T56 to SBC)
84-92 F-body bellhousing, fork, TO brg. (can maintain LT1 hydraulic slave in similar but inverse position; there are other hydraulic bell options, including aftermarket and C4 `vette)
LS_ clutch (lots of options since it's a light car)
extended pilot bushing as-needed. (probably needed since the LS_ has the crank a further depth from the bellhousing mating surface of the block.)

This would add length overall to the bell-to-tail length. He would not have to change his hydraulics.