Transmission Conversion

[Gadoozle]

I own a 1972 Chevy C10 that has a three speed on the column. I drive on the highway a lot, so fifty-five miles per hour in third gear kind of pushes it. How hard would it be to put in a four or preferably five speed manual transmission?

Thanks!

[raycow]

Originally Posted by Gadoozle

I own a 1972 Chevy C10 that has a three speed on the column. I drive on the highway a lot, so fifty-five miles per hour in third gear kind of pushes it. How hard would it be to put in a four or preferably five speed manual transmission?

Thanks!

The easiest swap would be a 3 speed + overdrive transmission, which was a factory option up to 69. This one is basically a bolt-in.

Second choice would be an A833/MY6 which was a factory option from about 82-87. This is a redesigned Mopar car 4 speed that gives you an overdrive 4th gear. The main problem with this one is that it is scarce. Also, some of them have an odd bolt pattern that requires a bellhousing swap.

Next, and probably easiest to find, is an S-10 5 speed. This one requires that you shorten the input shaft and bearing retainer or use an aftermarket spacer plate between the transmission and bellhousing. You will also need to shorten the driveshaft.

There are other possibilities, like a Tremec TKO (aftermarket only) or a T56, but they will be more expensive and require more modifications to install.

Ray

[Gadoozle]

Thanks raycow! If I were to use an S-10 five speed, would shortening the drive shaft be difficult? Would the transmission have to sit farther back, in order to keep the rear axle where it is? Sorry if any of these are stupid questions, I'm fairly new to this.

Thanks!

[57larry]

I used a setup from a 66 chevelle. bellhousing flywheel, clutch,muncie 4 speed, made a new crossmember. not a hard swap to make

[Gadoozle]

Thanks 57larry, I'll consider a chevelle when I disassemble my truck.

[Jacfourteen]

There is alot of info on here on the t5 (s10 tranny) swap, the only issue is that they won't take alot of abuse, anything over 300 HP is pushing it. There is also the NV4500 out of newer 3/4 ton and 1 ton chevys and dodges. Here are a few threads to look over to get an idea what's involved.

http://67-72chevytrucks.com/vboard/s...d.php?t=313954

http://67-72chevytrucks.com/vboard/s...light=T-5+swap

[Jacfourteen]

Forgot to ask what engine you are running?

[raycow]

Originally Posted by Gadoozle

If I were to use an S-10 five speed, would shortening the drive shaft be difficult? Would the transmission have to sit farther back, in order to keep the rear axle where it is?

If you have a salvage yard nearby, and time to measure driveshafts there, you may not have to shorten anything. If you are unsuccessful in finding a suitable length shaft, it is a very simple job for any driveshaft shop to shorten yours.

The S-10 transmission will bolt to your existing bellhousing, much as your 3 speed does now. The driveshaft needs to be shorter because the S-10 transmission is longer than your 3 speed. There is no need to move your rear axle.

Ray

[Gadoozle]

Originally Posted by Jacfourteen

Forgot to ask what engine you are running?

I have a Chevy 350.

[low'n slow]

A 4 speed from a car will not help you. The final drive ratio is 1:1 just like you have now. You need an overdrive transmission or a rear gear swap.

[Gadoozle]

Is there any way that I can go five speed and have over 300hp?

[raycow]

Originally Posted by Gadoozle

Is there any way that I can go five speed and have over 300hp?

Sure. You can use a Tremec TKO if you want a car type transmission or a NV4500 if you want a truck type (granny 1st gear). There is also a Richmond 5 speed OD (car type).

Ray

[Gadoozle]

Originally Posted by raycow

Sure. You can use a Tremec TKO if you want a car type transmission or a NV4500 if you want a truck type (granny 1st gear). There is also a Richmond 5 speed OD (car type).

Ray

Cool, thanks raycow.

[raycow]

On second thought, better forget about the Richmond unless you have bucket seats. The shifter on the Richmond can't be moved forward like the one on the Tremec.

Ray

[Gadoozle]

Would it work if I had a buddy seat? The middle seat doesn't take up as much space, but it's still a seat.

[raycow]

The Richmond shifter comes through the floor about 21" to the rear of the bellhousing face. This is about where the very end of your 3 speed is. Will that clear your buddy seat?

Ray

[Gadoozle]

Dang, it might work, but there's no hope of anyone ever sitting in the middle seat without getting in the way of the shifter. I think I may go the route of bucket seats with a center console.

[Gadoozle]

What would be a good transmission for a truck that would do well with an engine with over 300 hp? Are the ones you listed, the only ones applicable?

[7dguy]

Re-gear the ass end and call it good if you can live with a taller 1st.

[raycow]

Originally Posted by Gadoozle

Are the ones you listed, the only ones applicable?

There are two more I didn't mention, because you asked for a 5 speed. One is the T56 6 speed used in Camaros and also available in an aftermarket version. This one also allows the shifter to be moved forward by installing an aftermarket kit. There is also a Richmond 6 speed, but I can't see that it offers any advantages over the T56. It costs more than the T56 and doesn't allow the shifter to be relocated like the T56 does.

I think that about completes the list of commonly available manual overdrive transmissions suitable for high performance street use. If I missed any, no doubt someone will speak up.

Ray

[LockDoc]

-
Read post #12 in the second link Jacfourteen posted...

LockDoc

[Gadoozle]

Thanks Lockdoc, I'll have to read over these transmissions and decide which one I'm going to stick under the hood.

[haysonj]

Just put a gear vendors OD behind your 3 speed and you gain 22% I run about 2300 rpm at 65 mph with 4.09 gears and 35 in tires.

[Gadoozle]

Would that still work if I plan to lower it, and not use such large tires?

[haysonj]

Originally Posted by Gadoozle

Would that still work if I plan to lower it, and not use such large tires?

You will still get 22% better than you do now. So if you now run 3000 rpm at 60 mph with the GV you will run about 2400 rpm at 60