NEED HELP 4 speed to automatic and may be trade

[bkiller]

Hello guys i need to switch from a 4 speed with granny low to a auto trans for my 71 4x4 swb . MY WIFE CANT DRIVE LOL. What do i need, is the cross member the same, tranfer case the same . what spline is it, i would trade if some one wonts to the 4 speed only has 62.000 mile sence it was rebuilt , can i put a 700r4 in or will i have to stay with a 350 . any help would be awsome

[mrein3]

Originally Posted by bkiller

Hello guys i need to switch from a 4 speed with granny low to a auto trans for my 71 4x4 swb . MY WIFE CANT DRIVE LOL. What do i need, is the cross member the same, tranfer case the same . what spline is it, i would trade if some one wonts to the 4 speed only has 62.000 mile sence it was rebuilt , can i put a 700r4 in or will i have to stay with a 350 . any help would be awsome

All 1971 4x4s have the same crossmember and drive shafts. Everything else is different. All 1971's have a NP205 but the straight stick 205 is different than the auto 205. The stick 205s have a 10 spline input shaft. The auto a 28 spline.

GM put the crossmember in the same place on all configurations. The difference in transmission length is made up in the transfer case adapter. Each transmission has a specific adapter to mate up with the 205.

To put in a 700r4 - which never was offered in 1971 - you need to do some mods. You either leave the crossmember where it is, cut the rear driveshaft and lengthen the front OR leave the crossmember and move the engine forward approximately 1 7/8".

You also need to surf over to advanced adapters website and purchase a 700r4 used in place of a th350 output shaft. This needs to be installed in the 700r4. Write down the part number on the AA website and purchase that part from Summit. They sell it cheaper.

Finally you need a transfer case and adapter out of a 71 or 72 Blazer or pick-up that were behind a th350.

Don't forget you need a column shift steering column and all the column to transmission shift linkage. You also need transmission cooler lines and a radiator that has the tank in the side for the lines.

I've done the straight stick to th350 swap. I have not yet done the th350 to 700r4 swap.

[Liz]

Hey good luck in your quest. Just a side note that trades etc have to be in the classified section.

[bkiller]

thanks for the info

[bkiller]

Liz i cant post there it wont let me

[sdkid]

You must subscribe to post a classified listing. More about subscribing here.....

http://67-72chevytrucks.com/vboard/s...d.php?t=139629

[El Jay]

Dang!!
mrein3 pretty much covered everything for you.

If you don't want, or can't afford, to swap out radiators, you can mount an aftermarket transmission cooler to the front of your core support.
Just for a little added "protection", use steel braided lines, and be VERY careful in how you route them.