1985 GPz750 Unitrak Ignitor box / advancer

Hi All.
The GPz is running nicely on the road now after a few issues getting the carbs sorted, cleaned, jetted & balanced.
I'm running standard filter & box with an unknown make of stubby 4into 1 pipe with a 'reasonable' amount of baffle.
I've also converted to 530 chain & sprocket with 17T / 45T to give it a bit more zip off the line at the expense of top end, this is a little bit out & would benefit from a 44T on the rear (ordered), and standard 18" wheels.
So now my question ?
I'm sure I've read somewhere that igniter boxes from other GPz's with different advance curves work well on these bikes, any thoughts ?
Also, on previous bikes (ZXR's) I put on a 4deg ignition advance rotor on the crank end & this worked really well, are these available for the GPz750 Unitrak ?
I'm thinking one or other of these mods & could do with some advise.
Cheers.
Phil.

There are some details on the link below.
members.tripod.com/gpz_rider/technical/FAQ2000.htm

oldzed wrote: There are some details on the link below.
members.tripod.com/gpz_rider/technical/FAQ2000.htm

Perfect, that was the page I was thinking of but couldn't find. many thanks.