OK GUYS  I have a 1970 vert, tach has not worked in a while..and I disconected it from the distributor and turned the end  whith adrill.....tach indicates rpm. I guess the gear is probably shot..actually from what I have read...both the cross gear and the gear on the dist. shaft are probably both junk now so I guess I have to replace the distr. shaft and the cross gear. My buddies are telling me to get into the 20 th century and replace the dist. with a modern high voltage electronic ignition unit, I like things the way they left the factory so I am not really into that as a option, but am wondering if anybody has had  good experiance with this, and can recomend a good unit.......I guess I can always store the original anyway........Thanks for the advise E.M.

I would check with Eckler's or Mid America.

Wow...I'm surprised no-one has responded with any recommendations on this! I know a lot of youse guys have Mallory, Accell, MSD, etc. ignitions/distributors. How do they work for ya?

I would first pull the cross gear out of the dist and check it before doing anything else. Even if there is damage to the cross gear, it doesn't always mean the dist. shaft is bad too. The cross gear is bronze...the dist shaft is steel. The bronze will wear a bit more.
It could be the nylon "button" that keeps the cross gear centered has fell out, or melted, and the gear is just not contacting the dist. shaft.
Make sure the end of the cable that fits into the cross gear is still square...sometimes the end wears itself round, and then it just won't turn anymore. When you put a drill on it, you're clamping down on the cable, and it doesn't matter if the end is square, or round...it'll still turn. If you would like to keep it all in "original" looking/working condition, I'd spend a little more time investigating before giving up...that's just me...

Summit Racing sells an electronic billet distributor w/tach drive for $300 and an HEI with tach drive for about $225. MSD sells one for about $350.

I kept my 70 distributor in mine. I just added a points eliminator. I also have a bouncing needle sometimes. I investigated and thought I would take the shaft out and cross gear. Someone told me I needed to have a brass bushing made to keep the cross gear set and this would keep the needle from bouncing. I never got around to it and and the distributor has been this way for a couple of years now.

It sounds like your

I installed the Summit HEI distributor with Tach drive in the 69 about 4 months ago.  It works great.  It also has an adjustable vacuum advance.  No clearance problems.

just say a post on ebay last night for a 1970 dist. and the guy also has parts and rebuilds if i find it again i will try to tag it for ya.
L