I'm using a 89 car block - was in a T/A. it was a non-roller motor, but was drilled and tapped for roller, and still has the mech fuel pump boss with hole for the FP pushrod. pulled the cc268 out - somehow i never noticed the tapped threads for roller - i work on it late at night in the garage. decided to swap to roller, now here's where the dumb cam books lose me, I have 3 options, retro fit ( not for me, i'm not using a older block? ) then there's vehicles not originally equipped with hydraulic roller ( that's me ) and then there's vehicles originally equipped with hydraulic roller cam.. but what's the difference with the latter 2? they are different part numbers for the same cam grinds. I'm just missing the hardware and some essentials for the conversion, why are there 2 different cams with the same grind for non orig equipped and for orig equip? I can still use my cloyes true roller timing set up though right? since it's the roller with the solid pins? I don't wanna really fudge with the timing gear on the crank

 

retrofit = not originally equipped

There's only 2 types.

They are ground on different blanks. The "retrofit" ones have a nose that looks just like a regular cam; the factory roller type has the stepped nose for the retainer plate, and the smaller cam gear bolt circle.

If you're swapping from a flat tappet to a factory roller, you HAVE to change the crank gear. If you swap to the retrofit roller design, you may be able to re-use it, if you also re-use your chain (or use an identical one).

 

it's the crank gear from the cloyes roller timing set, not the original crank gear - that went in the trash a long time ago, forgot to point that out, still have to change it though? Which way is going to be easier for me? I was planning on using the comp cams kit for the conversion hardware. Yeah I see the difference on the nose - the cam gear isn't gonna work at all. It's new, I'll just throw it in with the cam/lifter sale, and toss the hardened pushrods in too. I don't even see roller timing sets for the small base circle timing, throw a P/N at me off jegs? I'll just pull the crank gear off and knock the new one on, not a big deal.