Good source for classic pontiac engine rebuild kit

So my gmc really needs a rebuild I think, no compression, severe vibrations at certain rpm, a lot of leaks etc. thats not so much the question, I have been researching rebuild kits for awhile for my 316 pontiac v8, 5.2 litre I believe...a couple of questions I have...

1...I have found rebuild kits but mainly on ebay, are these kits to be trusted or am I just getting cheap parts from china?

2...From reading the 347 is simply the same block with a higher stroke, would I be able to swap the crank from a 347 and buy a 347 rebuild kit?? Or is there more to it than that??

Thanks for the info ahead of time

 

try egge the make pistons

 

Kanter

 

Rockauto

 

Hmm i looked at egge and couldn't find one for the 316, I'll check the others