Solo from the back seat due to CG considerations?
Yes, those guys in the 60s were basically making their own Zlins, starting with a Chipmunk. Like Zlins the pilot ended up in the back after some iterations. The Ranger is a heavy six cylinder engine, as is the 260 HP GO-435 used later by Art Scholl. I think the weights and powers go something like this:
Gipsy Major, 145 HP, 310 lbs
Ranger L-440, 200 HP, 376 lbs
Lycoming GO-435, 260 HP, 440 lbs
Lycoming O-360, 180 HP, 260 lbs
Lycoming O-390, 210 HP, 310 lbs
A four cylinder Lycoming makes substantially more power than the Gipsy Major, with the same or less weight.