For some reason, the 300 in my E150 is sitting further back than it should. When I replaced the clutch and rebuilt the drive shaft, I had to use pry bars to get the transmission to line up as well as fab a bracket to move the carrier bearing further back. The previous owner mentioned that the engine had 50k miles on it. Whether that means the engine was rebuilt or pulled from another vehicle, i don't know. He knew very little about cars and had a mechanic do all the work.
I read on an F150 page that E150 engine mounts position the engine forward. I believe the PO's mechanic either pulled the motor from an F150, or used an F150 engine mount.

Now I'm curious if the engine serial number matches the body.

 

Hi Funke1,
I did a quick check on mounts and the one that fits the F150 was not a fit for the E150. If you have a friendly parts guy, ask to see one of each to determine if the offset is the same as the distance you are seeing in your case? jim