The Stovebolt Site Forums The Shop Area Engine Shop swapping trannies in 72 Chevy

I wnat to get rid of the original 3 speed column shift and install a 5spd form a late 80's full size Chevy 1500. Has anyoe done this, or can lend some help?

Hard to change the tranny without considering the rest of the driveline...

I don't have any specific knowledge (i.e. is it a direct bolt on). But you might be better off with a 4-spd from the 70's era - it will be better matched to the engine, and easier to install. Cheaper too, unless you already have one of them 5-speeds. Maybe still cheaper, if special adapter plates are required.

The top gear is going to be 1:1 for all trannys, unless there's an overdrive involved. So no change in top speed, just more shifts from 0 to 60. You'll have great torque (and much stronger leg and arm muscles) but no real drivability benefit.

If you were going to swap out the rear end for a higher gearing at the same time, then it makes more sense to go for the 5-speed. You'd get higher top speed, and similar power for the lower gears.

Otherwise the 4-speed is a better swap, and can probably be done in a weekend or three.

You will likely have to lengthen or shorten the driveshaft for any swap. Drive shaft shops can do this, probably $150 or so.

-Boyo

I think the tranny you're looking for is the NV 4500 out of 3/4, 1 tons and some 1/2's ? Or maybe the NV 3500? only found in 1/2 tons. I put a NV 4500 in my '76 if you need details drop me an email.

I know I can get a 4 spd from a 67 C/10 for $200. All that is really involved in the swap is the driveshaft, cross member, and cutting for the high hump. I have a feeling that will be the way to go.

Don't know about the 67's but the 66's didn't have a tranny mount crossmember. The rear mount was on the bell housing.

If it's an unmolested '67 it'll be a Synchro Mesh 420, if out of a '68 or later it's the SM465. I believe the transitional gearing is different -- the earlier tranny starting out even lower. Both are 1:1 in 4th, of course. Jeep and Toyota guys seem to think Muncie 420s are neater than sliced bread; I think it's a fit thing. The 465 is slightly longer, and if you have a '72, maybe you should look for a '68 or later SM465 if you want easy bolt-up capability. I know a '72 465 fit on my truck ['68] like it was made for it.

This is an SM465 tranny. Found out yesterday that only the cab was from a 67, the rest of the truck is a 69. I believe this tranny has the granny low gear to it???

If it's a sm465, it's a 4 speed granny box, with reverse to the right and down. Iirc, the change was made in 67.