71 vs. 69 question

[Rideto100]

I am brand new to this site and have really been impressed with what I have seen so far, there is some great info on here so I am hoping someone can answer a question for me.

I just purchased a 71 Cheyenne long bed that had been sitting for the last five years. Overall the truck is in great shape and I couldn't pass up the great deal. I had planned on cutting it down into a shortbed; however I just also came into the possession of a 69 shortbed without a bed. The 71 is still a very driveable truck but I want to do a frame off rebuild. I am going to completely rebuild the 69 frame before I start on the body. My question is could I also use the 69 cab in place of the 71 so I can keep driving the 71 as long as possible or are the cabs that much different. From comparing the two I can't see anything that jumps out at me but I know there are people on here having to modify their 69-70's to fit a 71-72 gas pedal.

I know this is a long post but any and all help would be greatly appreciated. The cabs are very similar in shape as in both have very little rust on them.-Jamie