Can I run a '98 & up clutch in '90 thru '93 primaries if I run a 66t ring gear

[gryphon]

I tried asking this question once before but I don't think I worded it right. I'd like to install the 1998 and later clutch in a bike with the '90 thru '93 primaries. These early clutches had a 66 tooth ring gear and used a different jackshaft. I can't run the later jackshaft in the early primaries but if I install a 66 tooth ring gear on the clutch (they make a conversion) will the gear align properly with the pinion gear on the early jackshaft. The tranny mainshaft is fine for the conversion. Only the jackshaft is wrong.

[fergy1940]

gryphon
Remember when I was changing my 84 flt over to belt that's exactly what I have works like a champ.

Fergy

[113evo1]

gryphon,
            keep in mind that in 1994 the big twin changed the primary drive ratio from the 24/37 primary gearing to the 25/36.
Most of the TwinCam clutch baskets have the 36 tooth gear except for the 1999 FLHT Ultra with FI which came with 37 teeth (HD 37846-99) and requires the 24 tooth compensation Sprocket gear.
I run the TwinCam style 24/37 clutch in my 94 FXR, the 25/36 primary gearing is great for freeway but every now and then I race my FXR at the local 1/4 mile Drag Strip. My motor is a S&S 113, came with 10 to 1 Compression Ratio with no compression releases… I installed a Spike 1.4 starter when I installed the motor and have had no problems with the stock starter ring gear.

[gryphon]

Yeah, I have the 25/36 combo in my bike. My son's bike has the 24/37 right now but I picked up a brand new late style clutch and VP plate to install in his. He currently has a 48 tooth rear wheel sprocket which I will swap out to a 51 tooth which will keep his ratio the same. that's one of the reasons I like chain drives so much. very easy to swap around. If I can help it I would just rather not have to swap out his primaries also.