need transmission advice...

[oldrusty]

Ok, so I got an old truck off craigslist, and had to swap the motor (badly abused/neglected 400sb out, built 85 Corvette 350 in) and now....of course....the transmission has issues that will force a rebuild. It has a TH350, and this truck will be used mainly for hauling 7k lbs of horses/trailer, as well as lots of hay, and maybe even used to pull trees out of the pasture (I will take pictures). The truck is a 1977 K20 Scottsdale, has a flatbed and an upgraded 1-ton dually rear end... eventually I will do a cab swap, but its gotta run before it can look nice!

The 91 Camaro the vette motor came out of has a 700 tranny that has issues also...but since I am going to have something rebuilt I wondered if the 700 can be used with my np203 transfer case? This truck is a learning experience, and I am not a mechanic...thank god for craigslist! I am buying parts and doing lots of reading here and elsewhere, and need some sound advice.

If I can use the 700, what is the best way to do the rebuild? Does the standard B&M transkit have everything I will need? What about a shift kit? Will that really help with a vehicle that is going to focus more on the low end? I will be running on the interstate, but nearly always with the 7k lbs of 'alternative crack habit' hitched to the rear end. (Crack would probably be cheaper than horses....)

If I stay with the TH350, same question. What parts will I need? This transmission seems to have pump issues - it pushes fluid out the dipstick, and with only 1/2 gallon of fluid added after the filter was changed (it looked like it had never been changed before!). It also 'hangs' when you shift into drive...it gets there, but it takes 15 seconds to do it. I will probably need to replace the pump if I rebuild this one?

A list of what I will need in addition to the B&M TransKit (or whatever equivalent y'all suggest) would be helpful...

Thanks to all in advance for letting me pick your brains! I found a guy locally to do the rebuild, I just need to go parts shopping...and y'all know how we women just love to shop, right? I would rather look for shiny truck stuff than shoes...

Speaking of shiny truck stuff, will the front clip/fenders/cab off a '63 fit on my 77 frame with the vetter motor, etc in it?? I know of one for sale, and mine is mostly rust and holes...if that doesnt work, there is a 69 setup around here too....