Hey Rob, welcome to CHR. That's a question that indeed comes up every once in a while, and in fact we just went through a lot of the issues with another guy on his thread about a '41 Chevy he's wanting to buy - Chevy SB and Automatic in S10 frame The same things apply to you, but even more due to the size of the Model A relative to the late model chassis, and the visibility of the chassis on the finished truck. The answer is to either use the original frame, or if it's not good buy replacement rails from American Stamping, Speedway, or one of the other shops out there and bring it back the way you want it.