Converting from farmer 4 speed to TH350

[1320feet]

What involved with converting from SM465 to a TH350. (1970 GMC 2500 2wd) Also, what aftermarket steering column would you recommend?

[pjmoreland]

Crossmember - You'll remove the original manual crossmember. It's riveted to the frame. You'll need to get yourself an automatic crossmember & transmission mount

Flex plate - this replaces your flywheel. You'll also need to remove the pilot bushing from the back of the crankshaft

Starter motor - you'll need one that attaches to the engine block instead of to the bell housing

Driveshaft - The TH350 uses a slip yoke as opposed to a fixed yoke, and the front section of the driveshaft is not telescoping

Shift linkage - You'll remove your clutch pedal and linkage, and you'll need to get shift linkage for the auto. Another option would be to go with an auto floor shift setup, which would mean you wouldn't have to replace your steering column. The original shifter hole in your floor will need to be patched up.

Neutral safety switch/reverse lights - These circuits will need to be rewired. If you get an auto steering column, then the neutral safety switch is on the column

Kickdown bracket - You'll need to attach the kickdown cable to your carb

Vacuum modulator - You'll need a fitting on your intake manifold for the TH350 vacuum connection

Radiator - You'll either need one that has a trans cooler built into it, or you'll need to add a separate trans cooler to the front of your existing radiator

Speedometer calibration - you'll likely need to replace the speedo gears in the TH350 to match your rear end gearing and tire size

If you are moving the engine to the forward mounting position like they did for factory equipped 2WD V8 trucks, then your exhaust will need to be extended, and you may need a different fan shroud.

[1320feet]

Assume breakdown.Thank you.

[davischevy]

Originally Posted by pjmoreland

Crossmember - You'll remove the original manual crossmember. It's riveted to the frame. You'll need to get yourself an automatic crossmember

Flex plate - this replaces your flywheel. You'll also need to remove the pilot bushing from the back of the crankshaft

Starter motor - you'll need one that attaches to the engine block instead of to the bell housing

Driveshaft - The TH350 uses a slip yoke as opposed to a fixed yoke, and the front section of the driveshaft is not telescoping

Shift linkage - You'll remove your clutch pedal and linkage, and you'll need to get shift linkage for the auto. Another option would be to go with an auto floor shift setup, which would mean you wouldn't have to replace your steering column

Neutral safety switch/reverse lights - These circuits will need to be rewired. If you get an auto steering column, then the neutral safety switch is on the column

Kickdown bracket - You'll need to attach the kickdown cable to your carb

Vacuum modulator - You'll need a fitting on your intake manifold for the TH350 vacuum connection

Radiator - You'll either need one that has a trans cooler built into it, or you'll need to add a separate trans cooler to the front of your existing radiator

Speedometer calibration - you'll likely need to replace the speedo gears in the TH350 to match your rear end gearing and tire size

If you decide to move the engine to the forward mounting position like they did for factory equipped automatic trucks, then your exhaust will need to be extended, and you may need a different fan shroud.

And therapy when your done, you will need therapy.

[special-K]

Originally Posted by pjmoreland

Crossmember - You'll remove the original manual crossmember. It's riveted to the frame. You'll need to get yourself an automatic crossmember

Flex plate - this replaces your flywheel. You'll also need to remove the pilot bushing from the back of the crankshaft

Starter motor - you'll need one that ..............

There's your answer. I'll only add remove clutch pedal. The simplest answer is buy a donor truck. That's how I've gone that swap before. Nothing to it then. 4wds are easier when it comes to this swap