So it's time to replace my 4.3 in my 91 Vandura, I am considering a 4.3 vortec and a manual transmission. What difficulties should I expect to run into and what parts and transmission should I be looking for?
thanks

 

I’m pretty sure that the crankshafts are different

 

​I'm talking about fitting a new engine and trans. Mounting points might be different, driveshaft length, I don't know. But a manual van with a floor mount shifter would be pretty sweet

 

I understand what you're talking about. I said I'm pretty sure the engines are different depending if you're hooking it up to a manual or automatic, so that's something to keep in mind, since you asked.
The vans haven't had a manual transmission since the 80's (before yours), so you're looking for some old equipment, and likely some custom mounting.

 

Any problem getting a manual engine and trans from a truck? Will a truck engine bolt right into a van?

 

no clue. You are venturing in custom territory which means doing your own measuring and fabbing.

 

You're going to have to come up with some sort of shifter linkage to have the shifter on the floor. In a truck the engine is up front with the tranny between the front seats. In a van the shifter would come up too far back to be practical.

You'd have to rig up something like a front drive manual has where the stick goes into a shifting mechanism bolted to the floor and transerres the movements to the tranny through cables or rods.

 

Yeah that would be necessary but shouldn't be too difficult. Lot of options available.
Now if I'm going to all that effort, maybe I should just center mount a twin turbo LS and make a GMC super van!