Looking for some information to help me solve a problem I currently have fitting a new timing chain and sprockets to my "92" F150. I had a water pump stud rust out and in the proces of fixing it I ended up down to the timing chain cover and decided while I was in there I would replace the chain and sprokets. My VIN number indicates that I have a 351 and my EFI has 5.8 on the intake, however when I went to my local parts store and brought the chain and sproket set home the timing mark was in the wrong place place on the crank sproket (mine is in line with the key way slot) and then crankshaft sproket was too big to fit under the cover. The parts store rechecked and called the dealer and for sure had given me the right chain set. I am now wondering if the previous owner had switched out the block and if so what do I have. I tryed to get some casting numbers on the block, but can't see them with the engine installed. If anyone has any clues on how to solve this problem I would greatly appreciate it, thanks

You probably have a left over motor from the 88 to 91 range look at the manufacturing date if it’s an early year production it could be an 88 to 91. all V8 from 92 to 98 have the same crank gear 5.0L, 5.8L, 5.8L-W-5.0L, 5.8l. The same is true with the 88 to 91 crank gear. But the 88 to 91gear is different than the 92 to 98 gear