shopping for a 302 long block

I have a 1976 bronco and have been shopping for a 302 long block. I have heard that the 1970 - 73 long block is better than the 1976 (more horse power). Is this true and why.. second questions is places like autozone have them for around 1400 as jasper has them for around 2000,, it there really a big difference in quality, I will be installing myself and keeping it stock for with a 2 barrel carb. possibly later I will add efi..

Early engines had higher compression ratio. When you order from a rebuilder, you will possibly get an engine with a mix of casting and date codes. You would have to ask for a specific ratio if you wanted one like the early engines. Jasper sells mostly to large companies with a fleet of cars or trucks. The more you buy, the less you pay.