Hi,
I changed my original distributor to a summit racing H.E.I. distributor. short time after changing my tachometer broke down. i bridged it and now at least the car runs… but i have a new original tachometer and I want to know if i need some sort of signal filter between distributor and tachometer . I do not want to have the other tachometer get broken too…
I have a 68 XR7 with the 302 J-Code Engine…
I hope you can help me.
Thnx Bavarian.
You have two options: MSD 8920 taking Tach output of dist to feed the 8920 and the 8920 in turn feeds the tach. Or, one of Rocketman’s three wire tach’s.
Go with the three wire tach. It is a permanent solution that won’t ever leave you stranded, plus you can also get the *K RPM version that looks like stock.
Rocketman does amazing work. He rebuilt my original tach and it is dead-on accurate. I also had him convert the Amp gauge to Volts. In the event that you wish to keep your dash original, I have an MSD 8920 Tach adapter that I would let go for a deal. PM me if you are interested.
I could never get the Tach Adapter to work. So I instead had Rocketman convert my tach. I believe I was one of THE FIRST customers to have it done outside of his prototypes. It has been in the car working flawlessly since 2005.
One of the problems or fears is that i got to get that part safe to germany… Is that rocketman’s tacho hard to install? I am no mechanic… i am working in law enforcement. so i am not the professional guy with working on cars. 
It’s very easy. The three wires:
1- 12V power
2- ground
3- signal from the ignition system.
Bob would provide clear instructions and I’m sure he’d pack it safely for the trip across the pond. He’d even stand behind it if there were any problems.
Go with the Rocketman Tach, like everyone above has said they are great…keep an eye on the Summit Racing HEI, they are very reasonably priced but the quality of the distributors are poor.
I ran a Proform HEI in my car for about 2 years (they are almost carbon copy of the Summit Brand), the vacuum advance can lasted about a year, the coil failed in it last November, when it failed I pulled the distributor out to check a few other things, with the distributor out of the car I discovered the bushings on the shaft were shot and the mech advance was also very worn and sticky.I replaced It with a Davis Unified in November (about twice the price) but the quality is there and it is surprising how well the car is running now.
Been running the MSD tach adapter for 20 years in the green GT-E. The ignition voltage no longer goes through the tachometer, so no way the tach failing can ever cause the car to stop running ever again. Super simple to connect properly, using the instructions on page two:
http://www.jegs.com/InstallationInstructions/100/121/121-8920.pdf
You can view the 3-wire tachometer wiring instructions here: http://www.rccinnovations.com/Instructions/XR7Tach.pdf
Are you a member of the Cougar Club of Germany? Do you have a local Mustang Club? I do a lot of group sales to clubs in Germany, you could save some on shipping if you can get included in one of their orders (I do not have any open orders going to Germany right now).
Shipping a tachometer to Germany using Priority Mail with insurance is currently $35.00. If it’s more than that I pay the difference, if it’s less I will refund the difference to you.
My Cougar Club of Germany contact is Timon Loeffler. He is in Bavaria as well. If you like I can PM his email address to you.
Hi Bob, that would be very kind of you. So i can get in touch with Timon… And of course i am member of the Cougar Club of Germany.
PM sent.