Author Topic: HEI tach help  (Read 425 times)

tmd171

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HEI tach help
« on: January 16, 2022, 08:33:10 AM »
Does anybody know if an HEI tach can work with a points distributor?

5th T/A

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Re: HEI tach help
« Reply #1 on: January 16, 2022, 09:59:25 AM »
Are you referring to a GM factory tach?

I believe Firebirds used the same tach in 73-75. 1973 would have been a points distributor while 1975 came standard with HEI.

1980 T/A with a Pontiac 461

Gone but not forgotten;
1973 T/A 455
1975 T/A 400
1978 T/A W72
1982 T/A cross fire injected

Two wheel toys;
2014 Harley Ultra Classic Limited
2013 Honda CB1100
2010 Yamaha Vmax
1982 Yamaha Seca 750

chief poncho

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Re: HEI tach help
« Reply #2 on: January 19, 2022, 02:04:43 PM »
Yes it should work fine.  I ran an HEI on my '71 with an original '71 Tach with no issue.  Just hook up the tach wire that normally goes to the coil to the tach output from the distributor. 

1971 Lucerne Blue Trans Am (455HO, Automatic) - currently my project car.
Previously Owned TA's/Musclecars: 2002 Pewter WS6/M6 Trans Am, 1968 Dodge Superbee 383/4speed,  1975 TA 455/4speed, 1989 Mustang LX 5.0/5speed, 1980 TA Indy Pace Car, 1977 TA 400/Auto, 1989 GTA 350TPI, 1990 GTA 350TPI, 1986 IROC 305TPI, 1989 Mustang LX 5.0/Auto, 1993 Mitsu 3000GT VR4 (and probably a few I've forgotten about)

chief poncho

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Re: HEI tach help
« Reply #3 on: January 19, 2022, 02:33:36 PM »
Whoops, just reread the original post.  You're asking the opposite question, will an HEI tach work with a point's distributor, I just answered that a points tach would work with an HEI distributor.

To answer the question, I believe the answer is the same.  Just run the wire that normally goes to the Tach output of the HEI to the negative terminal of the coil.  It should be a two wire tach and the other line should run to a 12V source when the key is on.
1971 Lucerne Blue Trans Am (455HO, Automatic) - currently my project car.
Previously Owned TA's/Musclecars: 2002 Pewter WS6/M6 Trans Am, 1968 Dodge Superbee 383/4speed,  1975 TA 455/4speed, 1989 Mustang LX 5.0/5speed, 1980 TA Indy Pace Car, 1977 TA 400/Auto, 1989 GTA 350TPI, 1990 GTA 350TPI, 1986 IROC 305TPI, 1989 Mustang LX 5.0/Auto, 1993 Mitsu 3000GT VR4 (and probably a few I've forgotten about)

Re: HEI tach help
« Reply #3 on: January 19, 2022, 02:33:36 PM »
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