I do not understand all this rubber sleeve and o ring stuff, even in the military we had size specific tools.

Ive done near 250 small blocks with these and never had one single issue, even to reuse the cam bearings from the race motors in dirt track claimer builds.

I dont know how the Les tool works but ive caught 3 MP cam bearings that were sized wrong from the box with these as well by not fitting or fitting too loose.

Maybe I just know there might be a better way or ?

sleeve or o-ring allows a split mandrel to fit a range of sizes...you don't need bearing specific mandrels. Just this winter I've done a small chevy, a 400 olds, and a small mopar. The adjustable mandrels cover all the applications.

Those solid drivers are nice. I ran into the same problem with a set of cam bearings where one was the wrong size. Would not fit the cam. Now I check that they at least fit the cam before installing them.

Funny , I bought my Lisle tool off the snap on truck ...

I use it for more than cam bearings . I could use another set of sleeves for it .

Might be able to get them here.

https://www.summitracing.com/parts/pow-pow181800

thanks John

Very welcome. Glad I could help