Welcome Tim!
First off, 'styleside' are the flat sided trucks.
You have a lovely example of a Flareside!
As such, you're the latest member of our FOG! (flareside owners group)
And the 300/4.9 are well liked around here.
Hoping we have all the answers and data you need to get your dad's truck running great.
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.