Transmission question

[hollywood763]

The transmission in my 66 3/4 ton truck is a 4sp with a granny low, and I'm replacing that transmission with another 4sp granny low that's out of a 66 half ton.
will this swap strait across or is there a difference between the half ton trannys and 3/4 ton trannys to where there has to be some modifications made?

I found this transmission on craigslist and I don't want to bother with buying it unless it's an easy swap.

thanks.

[blackedoutharley]

Provided that you're dealing with both transmissions being SM420's (reverse is towards the driver and down is easiest way to tell) it is a straight swap. The '66 trans may have a provision for back up lights but otherwise they should be the same.

Don't forget to drain and fill with fresh gear oil.

[jarkill]

If the half ton your getting it out of is a short box, double check the U joint size on the tail shaft. It may be different. Mine was

[padresag]

it is a different style of yoke, depending on whether or not that it is a one piece d/shaft or 2 piece. being as there is no s/bed 3/4t they do not have a 1 piece d/shaft
ron

[hollywood763]

The Transmission came out of a 1966 short bed stepside.

Could I switch the yoke out of the transmission that's in my truck now into the other transmission?