is exact originality a must for this machine? MOST parts will interchange between K series and magnum. Only difference is Magnum has no points, is electronic ignition. Shrouding and aluminum block "closure plate" are different and the magnum doesn't have the hole fo the points pushrod or point cover screws
. A few years back I spent a lot of time at the kohler site comparing some things. Same head and crank, you can use a K crank in a Magnum but not the other way around (Mag has no cam surface for the point pushrod, otherwise identical)
there is a before/after piston and rod for the late K series/early M series; the "early" goes all the way back to the 1st K 301s, the "late" came in a couple years after they stopped building Ks and switched to all M's.
You can use either early or late piston, rod and rings, BUT you have to use all early or all late parts among those 3 components, no mixing or matching.
cranks will also interchange between a K and an M.
Also you gotta consider the pan configuration. I have seen "wide" and "narrow" K series pans, but all the Magnums (that I have seen so far, anyway) have had the "wide" oil pan. If you have a Deere or a Cub that may well be an issue.
the other issue... You are not there to mike the block youself; It may have had a STD piston in it, but who knows how out of round or tapered that bore is? Yeah/ you could put it back together standard but if the bore is worn it won't last very long before you find yourself with an oil thirsty "fresh" rebuild.
Edited by dodge trucker, January 22, 2015 - 10:10 PM.