The 302 block is probably the easiest to find, in cars ranging from the 1968 and up Mustangs, Cougars, Mavericks and Comets, to fullsize sedans, and many pickup trucks. Most 302 blocks are largely the same, with some exceptions. Mid-70s "Mexican block" 302s are the gem of junkyards. Found in vans and midsized trucks, this extra-strong casting has "hencho en mexico" (made in mexico) cast somewhere in the lifter valley. These have been used in applications as high as 700 horsepower, due to a higher nickel content and larger main bearing caps. Any 302 block prior to '78 will be stronger then a '78+ or roller-cam block. Another quick way to spot these at a junkyard is an additional unmachined boss poking out of the front of the driver side cylinder bank.