Thomas I think your thinking a little too much about the strength of these motors. All the thrust washer mods and super-heavy duty stuff only needs to be done with high power, high buck motors. Any big kz motor will be bullet proof with a welded crank, APE studs, main cap and new cam chain. You can dump a ton of money into making the bottom end worthy of top fuel but you will never come close to needing it. Don't get me wrong, I'm a big fan of having a strong bottom end, only because it will save you from having to go in again to have the crank welded or whatever if you want to go bigger in the future. But putting 3 or 4 thousand into mods you will never need is a waist when you can spend that money where it is needed-in the head and carbs. Don't worry about how strong the cases are. they are plenty tough and will hold up to whatever you throw at them.
Rathdrum Idaho
1971 Kawasaki g3ss
1972 Yamaha R5 350
1965 Suzuki Hillbilly
1964 Yamaha 125
