I'll give you 2 numbers
H35-45304h This is an actual Rupp specific H35 number from a 1970 rupp scrambler
H35-45342h This is a standard mini bike/recreational setup configuration (from a 1971 Powerdyne mini bike)
A Rupp specific H35 will be a ball bearing 3" crankshaft engine, if its off just about anything else its a bushing sidecover and like 2 7/8" shaft length sometimes 3". Since your working with kind of a Mutt bike you cant really tell until you pull the driver off the shaft to see what the seal looks like.
For the basic rebuild parts (gaskets, rings, piston, rod, etc..) they will all cross between both those numbers. The side cover seal though will be different between the 2 so once you figure that out you can just use whichever numbers fit the bill. The Rupp number are for a 1970 model so it most likely wont pull up your carburetor rebuild part numbers (they didnt invent the slanted intake yet in 1970 so they used a diaphragm carb) but the other one will......The only internal difference between these would be the crank and side covers.
Also its important to know that if it is a bearing supported crankshaft the crank seal needs to be pulled off to get to the C clip that is on the crankshaft in order to slide the side cover off. The bushing engines are not clipped in they just slide off and you pop the seal out off the engine.
on the left is a ball bearing sidecover, right is a bushing cover:
good luck with it :thumbsup: