LiveandLetDrive

I eventually plan on doing an auto to manual swap in my car, but the Tremec 5speeds are looking a little pricey for my budget. What chance is there of rebuilding an old Muncie or SuperT10 with a new gearset... but different gears? Make the first 3 around what my TH350 is (or better) and the 4th to be a .7 or so overdrive? I couldn't find anything with a search, but surely this has come up before. Is there something else that uses gears like this, or would I have to have custom ones made? Does changing the gears cause other problems within the trans?

Also wondering if this is possible starting with the 5-speed, and having 2 OD gears? Would it just be better to get a very low 1st gear and switch to an even lower (numberwise) rearend? Is there a limit at which something mechanically bad happens? Do they even make anything much smaller than the 3.08 I have now?

-Chris

white74

I read in the tech advice section of superchevy that due to either the design or the cost of having custom parts machined your idea was not an alternative to the od tranny. I would do a search on the tko because someone on the forum had advice on where to buy one fairly cheap.

Vetterodder

If your goal is just to get an overdrive, swapping in a TH200 or Th700 4spd od auto will probably be the least expensive option. While it's possible to change gear ratios for 1-3 in a Muncie or BW, 4th will still be 1-1. The cost of buying and then modifying the 4spd, plus the cost of changing your rear gears to get the desired results makes the Tremec look a lot better. With the Tremec you'd have 4 speeds plus overdrive instead of a 3 spd overdrive.

Chuck Harmon

With a carbureted engine, you will not gain much by going to a lower numerical gear. Even your gas mileage will not change by very much. The percentage gain will be less than percentage drop in rpm's. This is because a carb'd engine is more efficient at higher rpm's than it is at idle. You need good airflow to atomize the fuel with a carb'd engine. Unless you have a very powerful engine, you will not be able to push the air any faster than the 3.08's will take you either, if you can even go that fast.

Look for a Super T-10 with 2.64 1st gear (or even higher numerically). This will give you great off the line performance with a good cruising gear.

Chuck

LiveandLetDrive

This wasn't intended to match up with my current engine, obviously I dont' have the power for the highspeeds right now. I hadn't thought of the better atomization at higher RPMs. Looks like Tremec 5 or Richmond 6 it is for me, time to start saving.

Chuck Harmon

The ROD 6 speed was far and away the best modification I made to the car! I love it much more than the trans and shifter that comes with my ZO6.

Chuck