I'm posting this up for my buddy who has a 99 silverado with 5.3 in it, he has been looking at converting it to a manual transmission, but we really haven't been finding a whole lot of useful info. So far we know that a T56 will bolt up, but we wouldn't be able to keep the 4wd, so the only option looks like an nv4500 out of one of the heavy duty 6.0 trucks. Does anyone know if that transmission will accept the transfer case thats currently bolted to his 4L60E? Will the driveshafts be different? I think the trans is a lot shorter but we should be able to use the driveshafts out of the bigger truck I would guess?

 

u can still use a t56, you just need a divorced 205 t-case out of an old ford or international. it will require some custom fabbing tho, like crosmember and drivelines (definitely not a bolt on procedure!)

your best(easiest) route would be to find a manual from a 99+ truck with the same frame length and steal everything u need like all clutch parts and hydros,crossmember,drivelines,and maybe even the computer(?) cuz it will all bolt up. also try and find one that has the manual t-case cuz most were push button wich means u might have to steal the dash and buttons.