Depending on how you plan to use the truck. If you are going the be hauling loads I would use the NV4500 not sure about the 3550 I know that they where used in jeeps and some of them have been changed to 4500s. The T-5 is a great choice also and where used in 4.3 Lt S-10s but the 5spd box used in 4cld and 60*V6 S-10s is not a T-5 and barely up to the task of the 4cld S-10. The plus of the T-5 comes if you building a rod out of you truck it will shift more like a car. The NV4500 is going to shift like a pickup. Advance Adapters has a installation manual that covers both the NV4500 & 3550 in great depth. If you have found a 4500 at a good price I would go for it.
Oh fredoly thank you I fixed the link.
