1972 GMC Stepper Long Bed

[72longstepper]

Just bought the truck yesterday and in process of doing my parts inventory.
Truck is solid very little rust odometer shows 98K. Fun part is It "might" have a later year 327 and front disc conversion has already done. Rotors/brakes are shot in front. Three on the tree shifts as it should and other than needing a good cleaning, seats or a redo, and a few other cosmetic things she is good to go. Quick question--------any "simple" way to tell what rotors/pads I would need? I am going to gut out the interior and spray then put down insulation and put new seals on. Pros and cons on moving gas tank? Plan on buying some kick panels with built in speakers so not really in need of the little bit of room I would gain by taking out tank. Also saw a website that has a one piece side window option and they even offer power options for it. Anybody familiar with this. Jeggs has an engine dress up kit on sale for $179.00 that has quite a bit of pieces, anyone bought that? So many questions so little time.