Should I go Big block or Small block?

Go with the 340 if you have one. Great motor not too heavy. Personnally I don't like strokers. They are not natural. Have to cut deep into the block water jacket to clear the rod bolts and sometimes counterweights. My stroker (crate engine), let go in the machined cut between #3 and #5 cyclinders, pumping lots of antifreeze into the oil pan. That sucked!! I sent the block back to the mfg. and they added block seal. Bottom line.... strokers require cutting the block deep and that doesn't make sense. Perfect for creating stress risers and cracks!. You may get more hp from a small block but how long will it last!