questions

[muffintop]

Just got some questions maybe someone with experience can help me answer. iv never really worked on a car unless you count changing oil and air filters, but im good with a wrench.

i got a 75 chevy stair body, with np203, th350, 454, 3/4 rear and dana 40 in the front.

my question is since i got the cab off to primer and paint. iv decided i dont need a 454, but rather a 383 i got in the shop from my dad.

-will the 383 bolt to the th350 tranny, or do i need an additional adapter plate.

- is there a way of servicing the transfer case, or transmission while i have the body off and am able to work on them with ease? is it worth rebuilding either one. i.e. buying new bearings etc...

-how can i calculate my gearing in the rear diff? which spline do i count and what is the equation i can use. the truck sits on a 8inch lift with 33's

- the 454 i was told, was old and worn. i dont know its its been rebuilt before, but is it worth rebuilding? how can i tell?

thanks guys! sorry if the questions are a bit vague, iv been trying to do my research to learn as much as possible as soon as possible.