what you guys think i should do.
 

Ok well just two days ago i got the heads off the car. Ive been planning this rebuild for a while, and im finally down to the last and biggest decision of all, which cubes am i gonna run off of? 350,355, or 383.
I have two blocks. one in the car with pistons, rods, crank still inside. The other on a engine stand, bare block, previously bored .30. With this bore i wouldnt be able to do a 350 obvisouly, but the problem with that block is it didnt come with main caps, therefore i have to buy them and have them line honed. so heres my few questions. I basically made a list of what needs to be done to each block during the rebuild process.
Block in car:
-Removal from car
-Remove Pistons + Rods
-Have block cleaned and the cylinder walls checked out.
-Install new pistons and rods

Block out of car:
-Buy main caps.
-Install Crank
-Have it line honed with the crank(resuse stock one or new 355 crank)
-Install Rods + Pistons

If i go 355, do i need a new crank or can i reuse the one in the car if it is in good enough condition?

Should i use the block in the car, or the one out, and build from there, and just take the cost of buying main caps and getting it honed?

What is the difference in bore/stroke/etc for a 383 as that is an option also?

Im still kinda new at working on motors so i dont know the answers to these even tho they may seem dumb.

You can use a stock 3.48" stroke crank in a 350 or 355ci build. The crank should be checked and polished before reusing it. Depends what kind of HP level and RPM you are looking at. Stocker isn't the best for a huge power adder (blower, turbo, nitrous) or an engine turning 8,000rpm. Healthy normally aspirated engine - it will be fine.

A 383 requires a 3.75" stroke crank and a 4.030" bore. Consider an 0.020" overbore (381ci) for added cylinder wall strength, and bit of extra meat for a future rebuild. GM also sells a "383" that uses a 3.80 stroke with a 4.00" bore.... not many people use that approach.

so if i do my math right using a 4..030" bore with a stock stroke i will be netting a 355ci? that is sayin Ci=BxPixS

And it will be a turbo set-up running no more than 10#s in the future. Hope this helps. What brand/forged or cast should i use crankwise for this build. people have told me a regular cast steel will work find with that low boost

Yes....
-stock 350 (349.85ci) = 3.48" stroke x 4.000" bore
-355 (355.12ci) = 3.48" stroke x 4.030" bore

10# of boost from a turbo would probably work better with a forged crank.... but I'll let the "forced induction" experts handle that one.