This truck had the original torque tube drive rear end. Obviously, it needed to be changed to an open drive rear end for it to work with the 5 speed. One of the issues with this is that the spring mounts are offset from the centerline of the rear end. So, the locating holes in the new spring perches need to be drilled off center. In this case, it was 2".
I have not been able to find quality aftermarket spring perches that are not 2 1/2" wide. Most pre-60's cars and trucks had 1 3/4" wide springs. What usually ends up happening it that I start with these HERE and cut the necessary amount out of the center and he weld them back together. This also allows me to drill the locating hole anywhere I desire.
We found a surprise when the clutch was disassembled. The motor is a 235 from a 1958 Chevy. However, it had a 9" diameter clutch. All of these era Chevy trucks I have ever torn apart had 10" clutches in them. So when I ordered parts before the truck was delivered, naturally, I ordered a 10" clutch. The flywheel in the truck was either an early 235 or a 216 coarse tooth flywheel. Later 235's after '55 uses a slightly smaller flywheel with a fine tooth ring gear. The flywheels are interchangeable but you also have to change starters. Luckily, we had a 10" 1956 truck flywheel and starter in inventory.
As for the clutch, we went with a raised diaphragm pressure plate compared to the original style flat diaphragm pressure plate. There are several advantages to this. First, these clutches are much more forgiving. Secondly, they also can handle much more power and finally they use a standard GM short throwout bearing. They also bolt right up as they are a standard 10" GM clutch from the 60's. As for the clutch disc, we used a 9 11/16" diameter 4x4 S-10 blazer disc.
The new 10" clutch and flywheel on the left and the "original" 9" clutch on the right. An 11" flywheel is in the center. |
You can see the difference between the height of the two throwout bearings and pressure plates. |
The drive shaft was fairly straight forward. We used a '57 Chevy car drive shaft with 1310 u-joints. The "new" rear end used the same joint but the standard S-10 transmission yoke does not. It uses a 1344 u-joint with clips on the inside. This is easily solved with a conversion u-joint from MOOG. Part # 372. You can get them through Napa or Summit Racing. As for the length, we did have to shorten the shaft about 3"
First cut the weld... |
...knock out the end... |
...cut to length and then reassemble. |
Spring plates had to be made to accept the new U-bolts. Everything tightened down quite nicely and we were able to reuse the factory shock mounts. The new transmission looks right at home.