Jason found this EUBCO 12 volt alternator, part number #12190 at a local parts supplier. It provides 40 amps of power and its compact design make fitting it into your Forward Control truck much easier. I believe it is available through NAPA. ($248) Jason installed this unit in his FC-170 but I’m sure that installation in a FC-150 would not be a problem.
Here you can see a comparison between the compact EUBCO alternator and an alternator out of a 1980’s GM product. The smaller alternator makes placement much easier and provides sufficient power for most Forward Control needs.
Jason used the existing top bracket off the generator and used the original belt tensioner. It is mounted to the top water pump bolt.
The bottom mounting bracket is made out of a piece of 1’ x 3/16” flat stock. It can be welded or bolted on. Jason said it took longer to run the wire than make the bracket.
Here's a side view. No modifications to the doghouse were needed.
Here's a view from the top access panel.