4X4 350 TURBO TRANS & 4X4 700-R4 TRANS

I have a 1980 K10 truck, short bed, 4X4, are these two transmissions the same length, or will I have to modify the crossmember & or the driveshaft? Thanks alot, Dustin  

The 700R4 will be slightly longer than the TH. Without pulling out a tape measurer I would say approximately an inch and a half.  If you already have the 700, measure the distance between your 2 mating surfaces(the bellhousing and the tailhousing mounting surfaces) and compare these same dimensions with the TH. With the transfer case mounting directly to the tailhousing surface you should get an accurate measurement of how far back to transfer your holes.  Just remember that you need some sort of lock-up controller for the 700, also.  Several companies offer controllers in various configurations.  Bowler makes a really nice unit that only needs one wire for hook-up. Every thing else is pre-programmed into the electronic unit that plugs into the factory wiring port.  You get converter lock-up 8 seconds after the trans shifts into 4th gear and if you wire the unit into your break light switch, it will automatically unlocks when you slow down. The down side is, it's a little more pricey than the other kits, such as from Painless, which I beilieve runs off of the engine vacuum, but the simplicity of the Bowler kit caught my attention.


Also, you could check out TCI's website.  They have a link on there that has all of the dimensions for various transmissions, such as mounting points and mating surfaces.  One other thing you will want to consider is your drive-shaft length.  If your transfer case is moved back due to a longer transmission, this may affect them as well.