MSD Tach Option
 

Does anyone know if there is a certain year tach that works without modification with a MSD setup? I am putting carbs on my 3.2 with a 2.7 distributor with points and a MSD 6AL. I have been told to send my 73 tach to a place to have it adapted for the MSD which is fine but if there is a certain year stock tach that works that may be a less expensive route for me. Any ideas or do I have to get the tach adapted regardless of the year? Thanks for any input.

I can't help other than to say that I used an MSD for 4 or so years w/my '74 tach w/out any adapters or other mods to the tach itself. It worked fine as far as I could tell.

Tom

my 1970 tach works fine with MSD 6A, I also do have the 8910 tach adaptor and 8680 timing controller

75 tach with no adapter or mods here too.

My 80 works with no adapter.

I think it's a question of individual sensitivity. The MSD sends very weak pulses compared to the factory CD box. If your individual gauge is sensitive enough, it will work fine. Based on what I've seen, it's 50/50 that any given year/model will work or not without the adapter, but it seems to be 100% that it WILL work WITH the adapter.

81 no adapter

thanks for the replies. I wonder what the tach shops would do then to the tach that costs 160 bucks? Kind of makes me want to at least try my stock tach.

according to the 101 projects book, some tachs of all years will work fine w/o the adapter, and some need the adapter and no one knows why. you may as well try it w/o the adapter first.

2.7 dist
 

If you are using a 2.7 dist as it came out of a 2.7 the gear on the dist. is going to give you way to much gear backlash if you are using the 3.2 drive gear on the crank, from 84 on it is Clockwise rotation but they need the "large" CW dist gear, if you have the 3.2 dist swap the gears.

Mike Bruns JBRacing.com

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