The MSD tach adapter (part # 8920) used to be a larger more "electronic" looking box compared to the smaller sealed unit it is today. Anyone know if this box was better or had problems?

Thanks in advance

I went thru two of the newer ones. I eventually found the large old one, and it has worked since. Did you have a problem?

No problem, I am afforded the opportunity to buy an older model of the 8920 and was wondering if I should.

Thanks for your input.

There are at least three styles of the #8920 that I have seen. I do not know why.

I have the newest, thinest one. It hooked right up and have not been a problem. Check EBay to compare styles and prices.

I keep hearing that the newer thinner units are failing . . . .heat failure?

I too have a newer #8920 purchased from Summit about a year ago. I re-wired all of my ignition components and mounted them all on a aluminum plate to the firewall. So far, no problems.

If anyone out there is in need of an 8920, I have a brand new one that I ordered by mistake. Found out too late that I needed the other one for my Unilite distributor - oops! Will make someone that needs it a good deal, just drop me an e-mail at bob@dodgecarroll.com Thanks!

Bob #5042

I had not heard about one style of 8920 failing more than the other styles.

If you are concerned, it should not be too hard to fashion a simple heat shield between the 8920 and the headers. The shield could protect the other components mounted on the firewall from heat and road debris as well as keeping some of the heat out of the cabin.

Or you can do what I did I mounted mine up front with my msd 6 AL box. I had a new box fail on me, so I decided to move them both up front behind the battery so far no problems

I burned 2 of the newer 8920's they got hot and smoked. I finally got some advice from MSD... They said it could be low voltage. it will handle 16 volts all day, but if it drops below 11 it will overload from pulling too many amps. I have mine connected through a relay that gets power dirctly from the battery.