[BigJimZ28]

yes Pontiac used one basic size block for everything, with the exception of the later 265 and 301 low deck motors (as long as it is not one of them you will be ok)

so the tranny is an auto?
if so you need to do some thinking about what you want to do

I would start with a higher stall converter(but you will need to match it your cam and powerbandto get the most from it)

for that $ I would try for
stall converter
shift kit
cam
as much head work you can afford