Replacing neck and pup on '91 57RI P

I want to replace the neck on my '91 57RI P-Bass with a Warmoth Jazz style neck. The original p-neck has been worked hard and I've delt with two (worsening it seems) dead spots. I've played along time and have always worked with my hands and I've developed Athritus. A Jazz width is more comfortable these days. I also want to drop in a Fralin pup. The original pup is rather dull IMO.
Is there anything I should be aware of? Jazz heal/P-pocket issues? Other than the obvious "measurement taking" is there anything I need to watch out for? Can the existing Pbass bridge accommodate the Jazz neck spacings? If any of you folks have done something like this and care to share opinions or comments it would be appreciated.

Thanks,
Mark

I don't see any problems with your plan. The bridge is the same for a P or Jazz-same spacing.

I recently finished installing a Fender CIJ Jazz neck to a Pre body. Like you my hands aren't as young as they used to be. A very slight fit adjustment but nothing a few licks of a file couldn't fix.
I'd be more concerned about your tuners. Some RI tuners, like the CIJ's, are a smaller dia. than original Fenders or US replacements. You should check that out when ordering your replacement Jazz neck.
The bridge should work just fine. If you're still concerned then have a tech do a custom nut install for you. That way the strings spacing/bridge will match up perfectly.