a few questions for a restoration

[drivethechevy]

i just was given a 1970 chevy c/10 with a unknown size v8 a 3 speed manual and a 307 ratio rear end
now my questions are
how do i tell what size the motor is?
i was told by the fella that gave me the truck that he knows for shure its not a 350 and that he narrowed it down to either a 283 or a 327. how can i figure out if he is right on that or not and the acctualy size?

also the truck is not running and i wanna know if the 307 rear end (which is a 12 bolt) is a posi trax. so what should i look for with out taking it apart to find out? and what should i look for if i do take it apart?

another thing this is a 3 on the tree and the colum does not seem to have any variations from the automatic colum i have in a 68 c/20 with a 6 cylinder. so what i would like to know is could i switch the trany fro m maunal to automatic without a new colum? and if that is possible is there any special things i need to do for it to work?

in your own opinions which motor would you use for this restoration to a nice daliy driver, i have a 350 out of a 68 gmc, a 283 out of a 65 impala, and whatever the motor is in the 70 that was running within the last 2 years where as the others havent in atleast 10 years but were stored correctly. all motors r not running but r not stuck.
which would u chose to rebuild for a daily driver?


if u can help me out with this it would be great because i am just starting out working on vehicles, and i got a 68 c/20 with a inline 6 that i drive with a far from straight body, then a 68 gmc and a 70 chevy with cab rust issues that i am going to use parts from along with a cab from a 69 c20 to build myself a restored daily driver