Some info here, may help -
http://www.sump-publishing.co.uk/royal%20enfield%20bullet.htm1954 Royal Enfield Bullet
Specifications
Type: Air-cooled OHV single
Capacity: 346cc (350cc)
Bore & Stroke: 70mm x 90mm
BHP: 18 @ 5750rpm
Compression ratio: 6.2:1
Transmission: 4-speed, multi-plate wet clutch
Brakes: 6-inch drums front and rear
Electrics: 6-volt, magdyno
Front suspension: Telescopic,
two-way damped
Rear suspension: Swinging arm,
twin shock absorbers/dampers
Wheels: 3.25 x 19-inch front,
3.50 x 19-inch rear
Weight: 350lbs
Maximum speed: 70-75mph
Note the price in the "Smooth Speed" ad.....