I have a 56 f100 with a 272 and three speed manual tranny. I was looking at getting it rebuilt and the heads. So with the price that that wil cost and the amount of hp that i will get from doing so i am thinking I might as well get a bigger engine and put it in. So I am wondering what is the best engine size to go in and with the least amount of modifications. and if you are able to throw a round about price that it would cost that would be awesome. I also have 3 speed auto c6 trans with a ford 9 inch rear end and drive shaft that i was planing on using with a compatible engine. thanks all

PS is a 312 block the same as a 272 block?