The Guys are telling you right by saying if you can afford a 4 bolt ,buy it.However it depends on what you are going to do with it.I get the feeling you are working with a limited budget. if you just want a good street engine that you can take to the drags every now and then, a2 bolt will work just fine .You should be able ....to build a 350 horse 2 bolt with ease.If you want more than that go with the 4 bolt. good luck