Looking at the track in the background its a 1/2 mile racetrack, so its a short track frame, was a trackmaster or late sonic.
IF you follow the lower frame rails there is that trackmaster curve, from the head to the tail, and its got the big one peice spine, and the high swing arm point. they obviously just cut the lower rail out for the motor and swung it off that top support.
HAs a early Trackmaster tank and rear loop. Bates seat and pad, so im guessing very early 70's on the set up.
HAve no idea about the motor, just that Hartline bike you where looking at was 68s, look at the district letter its the same. BE near impossible for someone to run the same white plate number and district letter, this must be the other side of the wheelie bike in the pic.
Note BIKe also has the same front end, same tank, same seat. The grey/black bike paint foto may be how it ended up some years later then.
Whats the differance in the 2 motors, looks like the one you have in your bike just has the electric start section, case and cover look the same other wise, but im only going on what i can see in the fotos. I dont actually know shit on them big rigs
what got my attention was the stand, looks to go up and under, and those carbs look like a flat slide ?