i bought 2 crane cams a few years back part no.753901. I put one in the 97 tj i had at the time, this is where it gets a bit fuzzy, from memory i used a timing gear/chain set from a 258, and for some reason i remember reading in the instructions to use these gears and it even had the jeep part no. to order. Now, i want to use the other one in the tj i have at present and i cant find anywhere any of this info, did i just dream that bit up or what? From my web wheeling i can find no reason why there would be any difference in the timing sets, camshaft fits 199-258cu. As far as i know the other one is still going strong in my old jeep.