IS a MSD tach adapter needed?
 

I am installing a MSD box in my car with the engine swap I am doing. The engine is a modified 3.2L that uses a modified 964 type dual distributor (dual plugged engine) -- it has the guts of an SC distributor in the main part of the 964 to provide the triggering. This all goes into a '73 with the stock tach for that year car.

Do I need to buy the MSD tach adapter? Or is there -- for certain - some other way to hook up the tach?

I say for certain becuz I don't want to blow up the tach by experimenting. (!) The tach is the stock one for a 1973 car -- it is not the Carrera tach.

Thanks!

so you need to know,essentially,if an SC needs the tach adapter when using MSD...oh,but you`ve got the 73 factory tach...tricky.Did you already try MSD? Good luck amigo,l thought l had the answer for a second there but l think someone on the board must have a similar system and they`ll know.Sounds like a great set-up.Post pics when almost done(helps with the motivation)

I believe that the answer is going to be yes. I had to with my '69 tach. Are you still using the factory triggering electronics such as a Pertronix?

The truth is....nobody knows!

Besides Wayne saying it's confusing in his book, I say this because I needed one on my 72T with a Petronix installed, but my friend with a 73S and a Petronix did not. Go figure.

I'd buy one - it can always be returned if you don't need it and it's not too expensive - I think less than $50. It's better to have one on hand in case you try it without and it doesn't work. I, uh, speak from experience, if you know what i mean.

I don't think you need to worry about blowing up your tach. Try it without the adaptor and if it doesn't work then buy it.

When I put an MSD in my 69T, I tried it without the tach adapter and my tach would go up and down randomly (nothing alarming, just random). I drove it that way for a week at least. Bought the tach adaptor and everything worked fine (no fried tach).

Thats my experience...