2wd trans swap -- T350 to SM465

[jimfulco]

Looking to swap to a 465 in my '79 1/2-ton suburban w/T350. I may have found a donor truck in a '75 1-ton pickup whose owner is thinking about swapping to an automatic. What problems might I run into with the other truck being a 1-ton? I'd surely rather use a half-ton donor, but intact ones are rather scarce these days.

[TrailerTrash]

is the 1ton also 2wd?

[jimfulco]

Both are 2wd, both have 350 motors.

[Shady Rascal]

The 4 speed will require a tall hump for floorboard clearance.

[barry1982]

You should be okay.....I converted an 84 4 x4 auto to a SM465. BIG job .
Think the biggest pain was pulling the clutch/brake pedals from the donor truck and installing them in mine.

[hatzie]

The SM465 will usually have a fixed yoke and two piece prop shaft with a slip joint in the rear section. The pickup and Suburban have different wheelbases so the prop shafts probably won't swap directly. You'll need to get a prop shaft and carrier bearing crosspiece from a 1/2 ton Suburban or get a prop shaft made... This is the most obnoxious part of the swap.

Pedals;
The 1-ton may have hydroboost so the pushrod pin may be in a slightly different location than a vacuum booster pedals. Trade your AT pedals and Vacuum booster/Master Cylinder for the Hydroboost Master Cylinder and MT pedal set if you can.
You'll need the whole Z-Bar assembly with the return spring, block ball and, frame pivot mount. You'll want the clutch pushrod seal as well.

75 may or may not have a clutch starter interlock switch. If it does there will be a short adapter pigtail running over to the AT Neutral Safety switch plug near the base of the steering column. Unplug and liberate that pigtail.

The floor hump may be shorter than you need.

The SM465 has a backup lamp adapter pigtail. Liberate it from the 1-ton. It should unplug from the AT backup lamp plug near the base of the steering column and pull the grommet through the firewall along with the adapter plug. It'll plug right into the AT backup lamp plug on your truck.

If your donor was a 78 or later I'd consider swapping steering columns with the 1-ton. It's still doable even with a 75 but it's slightly more difficult. The harmonica connector from the signal switches doesn't match up between the 75 and the 79 so you'll need carefully to swap connectors from column to column to make it work. There may be other differences too.