I don't understand this

Ok, so y'all are aware of the GEP pistons that came out of the 70 that was converted to LP long before I bought it. They measure 4 3/4" from the top edge of the piston to the center of the wrist pin. I still have not cleared up what a salesman told me in regards to GEP piston measurements.

I located some genuine original John Deere LP pistons. The owner measured them and got 3 1/4". ???? They are too far away for me to measure them myself, so all I can do is assume this is correct, or not.

I'm confused on them being shorter. They look almost identical to the pistons from the 70. I know that the gas and LP 70 used the same head but a different block. My tractor had the original gas block in it, but used aftermarket LP pistons. Now if I could just find out what the exact difference is with the LP block. Supposed to have the same bore and stroke, from what I've read. I already know about the different exhaust manifold. The same connecting rods are used in both engines, as are the same push rods. Used the same valves, but the LP used different valve seats.

Have had two different people try to sell me entire 70LP tractors for parts, but it would be waisted money. One is a rust bucket that was rolled over at one time. The other is too nice to use for parts.

Decisions......decisions. (scratches head)