OK Guys, Sorry I need so much help on what most would conscider a very simple repair. My tach has not worked as the previous post suggest's, and I just disconected the cable from the tach and hooked a drill to it....the tach indicated rpm, so I guess the tack and the cable are OK.....looking in the catalogs there is a bronze or stainless steel  "tach drive gear assembly"...is this what I need to change or could something else be the problem...also...if so... wich do I want S/S or brze ? Also Can I take care of this problem WITHOUT pulling the distributor?? THANKS AGAIN, Eric M.

Eric,

You can remove the drive gear/housing with the dist in place. You will probably need to turn the dist a bit to get to it, tho, depending on where it happens to point.
The housing just screws into the dist. Soak it down with some penetrant(WD40, etc) first, as it may be stuck in there pretty good.
Unscrew the housing and pull it out with the drive gear. Check to see if the nylon "button"(between the end of the gear and the dist.) stays on the dist., or if it comes out stuck to the gear. If it is not there, it will need to be replaced...this is one of those "gotta have" items.
If the teeth of the drive gear are damaged, the mating teeth on the distributor are most like damaged also, and the dist. shaft will need replacing.
If the teeth on the drive gear are not damaged, check the end of the cable closely to see if it has "rounded" off, as it should be square where it fits into the drive gear. Then check to see if the drive gear itself has rounded off where the cable fits.
Unless you replace the distributor shaft, always use a bronze drive gear. They are much more forgiving than a steel gear. Some replacement dist. shafts are stainless, and may require the stainless type gear.
HTH

Just replaced my dist shaft and cross gear with the needle bearing type unit.  It costs a bit more but works really well and I shouldn't have any problems now.  Only took about an hour to do.  Just remember to make sure the little button that stays in the dist is there and in good condition and shim your new shaft and cam drive properly.