I just found a whole bunch of paper work on my 76 dodge explorer 260. It got a new motor in 97. A 440. the manual says it came with a smaller motor. It got headers put on at the same time. not sure how many miles on it now, but I know in the last few years it only went out 2 times a year. Trying to get all the little things working right.I'll keep in touch. Any ideas would be cool.