rtruffa

Aargh, I have a 73 and yesterday my tach started making noise and then the needle starting jumping all over the place . . . I have an MSD Electronic Ignition w/mechanical tach option . . . thinking about replacing the whole thing with an electronic tach . . . has anyone done that ??? was it hard to do ????

KenSny

Lube the cable.

doorgunner

And make sure the ends of the flexible drive core aor not frayed and also engage the female ends well. Also make sure the cable itself isn't in a bind from being positioned incorrectly.

rtruffa

Thanks for the suggestion but I already tried lubing the cable (checked the distributor end and it looks fine) - it seemed to make a difference at first but after driving about a mile it started making noise again so I suspect the years have taken their toll on the cable. I have given thought to replacing the cable it giving the effort that takes, I was considering going to an electronic tach (probably use the zip-corvette conversion kit) so I was wondering if anyone has done that and how hard it was to do.

409/409

Replacing the cable has got to be the easiest cheapest fix. Then it will be good as long as you live.

rtruffa

Thx- I Thought about that cause a new cable is the cheapest solution but since I have to tear into the dash to do that I wanted to know if anyone has done an electronic conversion and whether they thought it was worth it

zwede

I converted the tach on my '71 to electric. It's easy and the electric tach is much better than the mechanical one ever was. I used a '75-'77 tach as it bolts right in and then put an early face plate on it as I wanted a 6k redline (modified engine).

rtruffa

Very interesting solution - big thanks

zwede

Found a picture of it. I wanted to retain a factory look.

rtruffa

wow, that looks great

carriljc

I had/have a MSD Tach Drive 8572.

When I went to the RamJet 350 with MEFI -- I converted the tach to a 75-77 tach since it used a GM small cap efi distributor.

When I went to EZ-EFI 2.0; I then went back to my MSD 8572 distributor, locked it out, and I now use it with my MSD box to drive my same electric tach. (NOTE: With signal coming from MSD box- I had to remove the tach filter because otherwise it would start bouncing above 3500-4000 rpm...nice and steady now).

If I was going to an electric tach nowadays, then I would look for one of those conversion kits that alter your mechanical tach drive.

Here you go:
https://willcoxcorvette.com/corvette...-kit-1955-1974

Mine ended up costing about this much after I bought the replacement tach and the replacement board (old board was bad).

rtruffa

Thanks for the info . . .

JimT

have you checked the drive gear in the distributor? I had to replace mine several years ago. Remove the cable at the distributor then remove the gear housing. Examine the gear teeth and look for excessive wear.

rtruffa

thanks Jim, I just put a new msd distributor in so I'm hoping it's just the cable - I have one on order and have my fingers crossed