k241 with no model number cast in block
 

I have what i believe to be a k241 in a 100 i was under the impression that they always cast the model number into the block behind where the starter/pto basket pulley is but there is nothing there... I was hoping I would be lucky and it would be one of k241s that they used the 301 block to build. have you any of you guys ever run across a block without the model cast into it? or know if it means anything?

Only some of the blocks had the model cast into them. Most did not. The ones that did, some were marked as a K301 but were bored to the 241 size.

Ok do you know if you can bore a regular k241 block to the k301 std bore size and make it a 12 horse without any ill effects?

some yes, some no. you have to check how thick the castings are. I had 1 old 10 that I took to .090 over 14 bore (3.5). it was thicker than all the 14 blocks that I checked.
If you do decide to make it a 12 you would need a crank, rod and a oil pan also. strokes are different. if you just want to put a 12 piston on a 10 rod the wristpins are different size so you have to deal with that to. can be done just takes time and money.

The need for a different oil pan on a 12hp vs. 10 hp? Is that because the 12hp all had a deep sump oil pan? My 10's all have the flat pan. Is this a consistent thing? All K241s came with the flat pan? All K301s and above had the deep sump oil pan?

yep, because of the longer stroke. 10's were all flat and the 12, 14 and 16 had the bump on the bottom.

yeah i figured I would have to change all that... Maybe it would be easier to swap someone my k241 that needs rebuilt for a k301 that is in need of a rebuild