super m

[jdetig1]

i have a couple questions. is an m block the same as a super m block besides the bore sizes?how much should i shave my super m head without breaking anything( i have dome pistons). can i turn the governor up a couple hundred rmps without putting too much stress on the engine.

 

[Janicholson]

The blocks fit the tractor, (either) but the M block has smaller fundamental cylinder castings in the bore, and would need to be bored out to accept SM sleeves of any standard or oversize.
Many have taken .100" off (I do not know where the max is, and some core shifting might cause .100" to ruin a head. I do not advocate Going for it unless you are willing to pay the price of ruined heads. Piston clearance can be measured easily with a used gasket, and clay. on the piston.
Rpm is a function of cam design and carb flow. If it is stock in the cam and carb, rpm will help much less. If you want to use this tractor in the field, be careful ( I would not go past 2000 RPM unless the 2 dollar trophy is worth 2500 bucks). JimN