jsut picked up a 010 block with crank rods a newer pistons one bearing was spun and i can feel a ridge in that journal so that crank is trash. I have the 305 that came with the car could i use that crank and one of the rods ? Also i have an older 262 v8 could i use that crank and or one of those rods to put in to the 350 010 block that we are going to build and drop in the car. I have not rebuilt a motor since i was 16-18 now i am 43 and i have forgot most of all the engine stuff. son and i are working on a 88 iroc this winter thank you all.

305 is a shorter stroke, I am not sure about rod, and main journal size..... Not a direct swap. You can find new cranks pretty cheap, just pick up another one for your 350.

305 is smaller bore; 3.736 in × 3.48 in
350 4.000 in × 3.48 in

I recall reading although the stroke and journals are the same ;there is something about the crank counterweight balance ? that means you cant use one in the other.

Ooops. My bad. Haven't had to deal with that aspect of things for a bit.

Due to the fact that the 305 uses smaller pistons, the ballance will be off in a 350 I believe.

You can use the 305 crank,if you are balancing the roatating assembly.This sounds like a budget build,making that a less attractive option.
There are some good quality cast cranks on the market for less than 2 bills these days.You can't turn an old crank down for that hardly anymore.I'd suggest ordering a catalogue from Northern Auto Parts,and looking at places like Enginekits.com,great places to buy entry level performance and rebuild parts,and they have great prices.

Dimensionally it is a direct swap, but it won't be balanced the same.