Speedo sensor gear question
 

I recently put a RC SYE in my '99 XJ. It's on 32" tires. My speedo is way off. Looks like the gear on the new transfer case shaft is bigger in diameter than the one on the stock shaft. It looks like most of the kits are pretty much identical parts wise. I am thinking that the gear size and tire size are compounding the effect on a real reading.
does anyone have any or know of any info on aizing a speedo gear for the bigger gear on the SYE?