Which MSD Tach Adapter do I need?

[rennch]

I have an MSD 6AL on my 79 SC motor in my 69T. I see that MSD makes an 8910 and an 8920 Tach Adapter. I can get an 8920 for a great deal ($20, new). Will this work, or do I need the 8910?

Thanks.

[Steve@Rennsport]

Have you tried connecting the cars's black/purple tach wire to the tach terminal on the end of the MSD case?

Sometimes you don't need an adapter at all.

[rennch]

Mr. Steve,

I have indeed. No dice.

It worked for my 72, but not for my 79. Go figure.

what are you doing up so late? Go to bed!

[rennch]

Errr...that would be *69*, not *79*.