tach conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

chris989 · 10-01-2021, 10:08 PM

Hello all,

I was looking at the tach conversions at LMC for my 89 burb. The unit for 83-87 is still back ordered but the have ones for earlier models. Does anyone know if there is any difference in them other than the face of the gauge?

their tech support does not have details. USA1 has a conversion for 81-87 but it is 80$ more and looks the same.

I am guessing that the USA1 conversion will work with my 89?? 89-91 is the odd years were suburbans and one tons remained the old body styles.

Any guesses?

https://www.lmctruck.com/1973-91-che...onversion-kits

https://www.usa1industries.com/produ...roductid=20797

Pontiac1976 · 10-02-2021, 06:23 PM

Yes the face is the mostly for the year your working with. You will only be able to use 78 up 91 TACH, with the opening for light check at the bottom to work cluster. If you not going to have the check light under the tach/working or seen could go back more. But you have to do a little DIY: cluster they have the hole smaller 73 have no hole for the check lights under the Tach.

**THI** · 10-06-2021, 09:51 AM

1989 will be the same as 1981-1987 - 1990 & 1991 used a different speedometer so the housing for 90-91 is different. 1973-1977 used mechanical oil pressure gauge, 1978 up used electric oil pressure gauge.

I have a 1978 GMC K2500 I am working on that someone installed a 1981-1987 gauge cluster in it and it works fine.

chris989 · 02-11-2022, 09:03 PM

I finally received the tach conversion from LMC and have to say the kit is solid.

Everything is in there, the new black gauge cover didnot fit perfect so i re-used my OE one.

The tach is smooth and accurate and I think it was well worth the money. I know you can source old parts and put one together but if you value yout time this conversion is a no-brainer.

LMC can be hit or miss but this was a winner.

My only issue is the new fuel gauge seems to read high. takes a lone time to come off full.

Chris

**Factory Guy** · 02-14-2022, 11:58 PM

I wanted a 8000 rpm tach so i built my own.

10-01-2021, 10:08 PM	#1
chris989 Registered User Join Date: Dec 2011 Location: Boise, Idaho Posts: 572	tach conversion Hello all, I was looking at the tach conversions at LMC for my 89 burb. The unit for 83-87 is still back ordered but the have ones for earlier models. Does anyone know if there is any difference in them other than the face of the gauge? their tech support does not have details. USA1 has a conversion for 81-87 but it is 80$ more and looks the same. I am guessing that the USA1 conversion will work with my 89?? 89-91 is the odd years were suburbans and one tons remained the old body styles. Any guesses? https://www.lmctruck.com/1973-91-che...onversion-kits https://www.usa1industries.com/produ...roductid=20797

10-02-2021, 06:23 PM	#2
Pontiac1976 Registered User Join Date: Oct 2015 Location: Ottawa, Ontario, Canada Posts: 752	Re: tach conversion Yes the face is the mostly for the year your working with. You will only be able to use 78 up 91 TACH, with the opening for light check at the bottom to work cluster. If you not going to have the check light under the tach/working or seen could go back more. But you have to do a little DIY: cluster they have the hole smaller 73 have no hole for the check lights under the Tach. __________________ 1977 REG cab Long Bed with a 1984 Front Clip, 82 305 .60 over 9.0.1 flat top pistons, 4bbl, TH350, w/84 SS-intake & cam , w/ 1977 big block rad, 1975 gear box, 1984 master w/ metric fittings top & SAE fitting @ portion block, 1975 3.42 gear open diff. Duel 77-87 Factory air cleaner, duel inlet from rad support . Down sized 9' to new 8' Steel flat bed Was a 77 454 w/308 gear. Taken out 550 lbs. up front with motor clip change.

10-06-2021, 09:51 AM	#3
THI Active Member Join Date: Jan 2017 Location: Traverse City, MI Posts: 179	Re: tach conversion 1989 will be the same as 1981-1987 - 1990 & 1991 used a different speedometer so the housing for 90-91 is different. 1973-1977 used mechanical oil pressure gauge, 1978 up used electric oil pressure gauge. I have a 1978 GMC K2500 I am working on that someone installed a 1981-1987 gauge cluster in it and it works fine.

02-11-2022, 09:03 PM	#4
chris989 Registered User Join Date: Dec 2011 Location: Boise, Idaho Posts: 572	Update I finally received the tach conversion from LMC and have to say the kit is solid. Everything is in there, the new black gauge cover didnot fit perfect so i re-used my OE one. The tach is smooth and accurate and I think it was well worth the money. I know you can source old parts and put one together but if you value yout time this conversion is a no-brainer. LMC can be hit or miss but this was a winner. My only issue is the new fuel gauge seems to read high. takes a lone time to come off full. Chris

02-14-2022, 11:58 PM	#5
Factory Guy Senior Member Join Date: Jun 2019 Location: Midway USA Kentucky Posts: 562	Re: tach conversion I wanted a 8000 rpm tach so i built my own. Attached Images __________________ http://67-72chevytrucks.com/vboard/s...d.php?t=791250



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