I've got an 86 F-150 with the 300 Inline 6, but haven't figured out excactly where to find the block numbers (trying to figure out if an enigne swap has been done with different year). I found numbers on the plate between the block and the bellhousing, and the first 4 matched up to engine codes I'd seen elsewhere (C5AE), but that's from a 76-80 I believe... need the right info because it appears the truck came to me with an incorrect starter.... thanks for any help.

 

The first step you should try is to compare the calibration number on the valve cover decal with the calibration number on the emission decal under the hood. If they match, odds are it's the right engine. If they don't, then you know for sure it's not. I have a list of all the 1986 calibration numbers, if you want me to confirm it for you.