The Kips bolt mod was'nt aimed at making it start easier...it'll be just the oppisite,but not by much.It was aimed at getting a little more low-end grunt.
If you do a "search" for the thread "KIPS BOLT MOD",you will find exactly what you need to machine one yourself....but I'm not sure if the 87 K5 ever needed/benifited from this mod.
I made one myself by buying a new OEM KIPS plug...center punching the middle,then drill a 1/4-20 hole just deep enough so not to go all the way through...then took a 1/4-20 bolt and dabbed on some Yamabond and drove it in.Let the yamabond set for a few hours,then took it to the bench grinder and ground a little at a time off...keeping an eye on when the valves were just closed by looking up in the exhaust port.So far there's about a seasons worth of riding on it,and no issues.
I'm sure some of the members have some different methods that will work just fine as well.