I do a bit of towing with my 1985 G20, it's no secret that the 305 struggles with pulling anything over the van's own weight around. My original plan was to use the 305 until it showed signs of dying then swap to an LS, but after nearly 3 years of use, mostly towing a trailer with a car on it, the engine still seems to be in good shape. I figure I might as well try to make it's life a bit easier. Plus it will be nice to have that already taken care of when I do swap to LS power down the road.
The van currently has a 3:42 (RPO code GU6) rear gear and I want to swap it to a 4:10 with posi. I've done a bit of research, but I am used to the imports with independent rear suspensions and the differentials are much simpler to set up (less of the marking/painting/crush spacers/etc). The old GM rear ends seem a bit more complicated to set up plus I have no clue what the best parts are to buy.
So, my questions:
-What should I buy to convert my rear end to 4:10 with and without Posi? Trying to see what all the options are, but what brands should I look at vs avoid, etc.. What do you recommend?
-Also, what is a link to a good guide for setting up a rear gear like this one? I've read a few different "instructionals", but looking for something more technical with actual torque specs and such.
Thanks in advance!
Last edited by tuner4life; June 30th 2017 9:50 am.