440 rebuild

I am putting a 440 in my 1952 Dodge pickup that I have been driving for the last 19 years with the flat head 6. I'm using a late model frame, found an s-10 chevy with the correct wheel base, but am concerned about the crossmember. I would like to use a Dodge Dakota, but would have to shorten the frame. I was wondering if someone might help me with my engines. I have 2 440's. The first one is supposed to be a 1974 440 from a motorhome. The casting on the side of the block is 1115-74 and then out to the side is a 6. The heads are 4006452 which according to the mymopar.com casting guide are 1976 to 1978. I can't find the number on the block in the casting chart for blocks.The plate on the top of the motor has 5T 440 F and a 10 below that. I bought this engine with a 727 trans attached and have had it rebuilt. The other engine I have has 3698830 on the block which is a 73-78(chart) and the heads are 3769902-8 which the chart says is a 74. The plate on the top of engine says J440 and 7 T3 E2. I will be doing the engine myself, but I was trying to figure out what I have. The motorhome engine is supposed to only have 40,000 miles on it. I haven't pulled the heads yet to check for wear. I'm not wanting a drag car or anything like that, just nice power and streetability. I saw that someone on the forum said the 40064452 heads were the best. Thanks for any help. Randy