Jack Roush used to be in a partnership with a 'Wayne Gapp' back in the older days and they were really into drag racing in a big way under 'Gapp & Roush' signage.
Not sure about your '289', as I was more interested in what they were doing with the Boss302. This was way before the stroker kits were common, they sourced their stroker donor cranks from the 292 or 312 'Y' block ( forged steel truck version ), modded the flywheel flange to suit SBF and cut the snout length down for an easy ~358 cu inches with ~4.000" bore. Be interesting to see what you find in that '289'.