Well it looks like my factory three speed transmission is about to meet it's maker. The transmission shop tells me it would be best to look for a swap. They are looking for one. My original six speed engine was just rebuilt and runs like the day ... or maybe day after it came off of the assembly line. (I am very happy with it and don't want to change it.) I didn't ask the shop about this but thought maybe some of you might know what options I would have in swaping to some other transmission, maybe even going to an automatic (HA). I guess I'm dreaming but if I had more options in my search, maybe I could save a few bucks. I know that a TH350 can be swaped with a powerglide but, what about with the original 3 speed manual transmission? Truck specs... 66 C-10, 6 cyl, 230. Thanks!
How about a 5 speed manual ? The following is copied from another forum; Re: Finally, 5 speed sucess!!!!!! [Re: 66stepside] #560183 - 09/10/03 12:07 PM Parts-wise, it was pretty simple. Time was the challenge. I used the stock 3-speed bellhousing, linkage, clutch fork, flywheel, a stock pressure plate and TO bearing from Chevy Duty (great people!), along with a clutch disc with the correct 14-spline count (most discs for T-5 trannys are a little under 10" diameter, which is fine; check with Advance Auto or Auto Zone and look in their clutch book with sizes available; you would be surprised how many cars/trucks came with this basic tranny which gave me many choices/options on exact size needed), and all I needed to do was have my driveshaft shortened a couple of inches with new u-joints and a new slip yoke to fit the output shaft on the transmission (I got mine off a junkyard driveshaft--$15). All total, I think I have 8 hours total in the conversion. It didn't help that I needed to make 3 seperate trips to the machine shop to finally get the correct size u-joint for the rear end (I didn't know there were that many different rears used in 1/2 ton 2wd trucks? Oh well!)My frame has a tranny crossmember right under the tailshaft which didn't need to be moved, but even if yours does need moving, the 4 rivets are all that hold it on. Hope this helps!!
I just finished putting a 4 speed in my 1966 shortbed stepside. GREAT tranny! It's from an early 80s Chevrolet pickup. Fourth gear is overdrive. Fortunately this tranny was the same length as the smaller 3 speed. So the driveshaft didn't need modifications. I had to find a heavy duty style bellhousing (with a 5 1/8" diameter hole) but other than that everything else worked out great. This transmission has a 3.09 first gear and a 0.73 overdrive. Great for improved takeoff and easy cruising rpms! Some call it an 89MM; others call it an "MY-6". They're not very easy to come by so if you see one GET IT! Later!
