Hello, I'm thinking of using a NV3550 (5 speed) transmission for my LS swap. I know very little about this transmission other than it was used on the 99-06 4.8. I like my T56, but it is just such a pig of a trany, and I would like something smaller and lighter.

So has anyone used one of these in their swap? how big are these, like T5 size? weight? Is it just a stupid idea?

 

if you are planning on making some power....stick with the t56.

i can lift a t56 and put it on my bench....they are not that heavy!

 

You'd probably want the 4.3L S-10 version since they used a lower-profile shifter design and shorter throws independent of the stick length. Also, the version you referenced is a NV3500, only Jeeps got the 3550. The 3550 has an unboltable bellhousing. The version you referenced is geared 4.02 - 2.32 - 1.40 - 1.00 - 0.73, while some S-10s had 3.49 - 2.16 - 1.40 - 1.00 - 0.78, though the '96 C1500 5.7 combined the 0.73:1 with the 3.49:1, which would be the most desirable gearing of what the NV3500 offers.
There's no provision for the torque arm. There's no choice of shifter location, and it may end up too far forward.
Keep the T56, just replace the synchros and other wear items to make it less of a pig to shift.
I can't see why you'd consider this except for monetary reasons, and if it's not that, then test-drive someone else's TKO600.