I know this is bound to have been posted countless times but I couldn't find a good write up on what all is involved.

Anyway, we have an 89 SASed extended cab V6 running the old automatic. It has 35s and is geared 5.29. As you know, an auto isn't the best option for the 3.0. We have come across a five speed with transfer case and cross-member for $150, and are seriously considering this swap. It would make the truck MUCH better power and driveability-wise. There isn't a thing wrong with the automatic (its impossible to mess up the A304).

What all is involved? Obviously the flexplate must be swapped in favor of a flywheel. Will we need new driveshafts? Is there a way to fool the engine into thinking its in neutral all the time, so as to keep the old ECU? Any help is appreciated, and I would be willing to do a write-up whenever we get the chance to actually do the swap. Thanks!

 

You'll of course need the pedal assembly, master cylinder and slave.

Not sure if your 3.0 will have the crank drilled for a pilot bearing. I know the 3.4's are almost all drilled that way, despite the tranny the factory mated them to.

Need a new crossmember. My guess is your drive shafts would be close enough.

My bet is you'll need a 5spd ECM. A lot of the 3.4 swaps run into this problem, and I don't think anyone has found a good way to mate a auto ECM to a 5spd tranny. I actually have a '90 5spd 3.0 ECM for sale... if that would work for you.

Center console would have to be addressed, if you are worried about cosmetics.

Also, you might need a new transfer case if your current setup is one piece. You'll need an adapter at the very least. All that might effect your DS lengths I suppose.

 

Check this out:

https://www.yotatech.com/forums/f116...d-swap-117391/

I did mine about a year ago. Its a pretty easy swap.

I didnt need new D-shafts but ive heard of some needing them.
I bought a trans + Tcase and Xmember, pedal assembly, new clutch. MC, slave and lines. Also the shifter and boot and trim around the boot. I got everything from a junkyard except for the clutch and wearable parts.

 

Oh.
You dont need a 5speed ECM. Connecting 2 wires will make the computer think the truck is in neutral. Run those to your switches on your clutch pedal and your cruise will work and you will have to push the clutch to start the truck.

 

All 3.0 have crank that accepts pilot bearing. Crossmembers are the same, only the TC mount is different. Your front shaft will be OK, the rear one will need to be re-tubed about 2 1/2 " longer. You may have trouble getting ADD to work for 4WD, there's a thread on that here somewhere but lot's of differences in vehicles re: wire colors, etc. There are several different part no's for hard lines from the clutch MC to the slave, depends on if you have ABS or not. The clutch cover plate (sheet metal) is different from the auto, but the one from the auto can be made to fit. The rubber gasket on top of it is the same. You will need to cut the tranny hump a little for the TC shifter.

have fun

 

thanks for the help guys! i'll keep you updated on how it goes...

 

I didnt need a new driveshaft. I got the one that came off the truck anyway but they ended up being identical. I think the only differences are the tailshaft with a speedo gear or electronic.

There could be other differences though. But I lucked out.