Ive been searching on how to go about a T56 swap in a nnbs and havent found much. Is there any write ups here or elsewhere? Thanks

 

not an nnbs but still a fullsize and an ls engine

this could be pretty helpful to you, seems to be a t56 swap list for auto to manual and manual to manual.
T-56 Swap

 

lol you really wana do a t56 swap in a gmt900?

 

Daryn has done it.....he's the only one i know thats done it other than the rcsb that had a 5 lug swap, gto seats lowered an black. It was pure sexy

 

Mechanically its pretty straight forward. You'll need to make up a crossmember and if your truck is a 6spd auto you may need a new driveshaft. If its a 4L60E the t56 is the same length and spline out so stock driveshaft will fit but im not sure of the 6spd auto similarities or lack thereof.

Tune wise your in for some fun. Getting your speedo to work right might be problematic but this depends on your model year and current powertrain. Its also tricky to get these things to run properly without feeds from the TCM.

What year is your truck? Engine/trans?

 

sig says 08 so either way he has the 60e.

 

he will need a flash for a truck that has a 5 speed trans,other wise he will throw a code for not having trans hooked up. which may go into reduced power
the trans crossmember will sit a little low so he will have to lift the trans about 3/4''.
cutting a hole in the floor board.
notching the body of the truck underneath ( DRIVESHAFT WILL HIT)
drilling the hole for the truck clutch master and pedals,
making the special nut to finaggle behind the bracket under the dash to bolt the pedals
special russel fittings and 4AN hose for master and slave
if the struck is lowered you may need to shorten your driveshaft 1/2-3/4 inch maybe

 

I'm giving this a bump. Daryn, it seems like your opposed to it after you did the swap. What's the reason for that if you don't mind me asking. My truck has seemed to be drag racing use only so I drive it once a month. I miss just taking it out for a drive but the high stall takes away from that fun at times. I'd love to row some gears. I wouldn't care about it sucking at the track, I'd have no problem not racing it again.