NEED A 340, 383, or 440 BLOCK!!!!

I'm getting started on my drag car project and I'm lacking the most important part, the engine. I'm looking for any mid to late 60's engine blocks. From what I've been told, I should stick to a big block for low-budget high hp combination, but if you have any input then throw them out there. I'd prefer either a 440 or 383, but like I said, if you have some info on something else I should look into throw it out. Thanks!

Brad