As original, the fronts a tad narrower, the rears a tad wider than a Formula Ford, assuming that the mandated FF wheel width is the same as it is here. The tyres have changed more!
The tyres on a Kent engine Formula Ford are all limited to 5.5 inches.
The tyres on a Lotus 27 Formula Junior were 4.5 inches at front and 5.5 inches at rear.
On both cases they were on 13 inch wheels.