A 1971 Fox RC engine, the carb is epoxied into the cut off and drilled out venturi. It has a two jet carb with a cap restricting the intake. I assume the restriction was to improve fuel draw at the time. But it could have been a larger bore carb leftover from the older .59 and .60 engine production too and needed the intake to be reduced to work properly on the engine. The engines had something like a variation to Schuerle porting at the time, there wasn't a baffle on the piston like the crossflow scavenged engines had. George Aldrich was involved in the design of this engine too.

The engines pretty much stayed in production until circa 1975 when the new Fox large case Schuerle .40 and .45 engines with the high backplate on them came out.