[91chevywt]

I would look at swapping in a running 350 from an older truck or van from the 90's. It will be a world of improvement over the 305. If this is your first car, I wouldn't do a engine build at this point. Machine work is expensive. The cost of parts adds up quick. Its much easier to get something thats already running with a bit of mileage

If you plan on building from the ground up expect to budget at least $2-3k to do it right. A half assed motor will end up trash in a couple thousand miles.

or

fix what you've got and learn some stuff