Author Topic: LT1 Swap Temp Sender  (Read 311 times)

BubburzTheBandit

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LT1 Swap Temp Sender
« on: April 07, 2018, 06:42:57 PM »
Hello again, all. I have a 77 SE that I've swapped in an LT1 out of a 1994 Trans Am. I'm running the original gauges and all of them work except for the temp gauge. It's running off of the stock LT1 sending unit, which I now understand doesn't have the right resistance for the gauge to read correctly and why I've posted this in the electrical section. The originals were 1/2" NPT, and the LT1 unit is 3/8" NPT, so swapping them out isn't an option. I found some at Willcox Corvette that says it works for the gauge in a 1977 Corvette and has 3/8" threads. My question is, would any of you electrical guys know if this would work for the Trans Am gauge? I didn't know if the resistance needed for the gauge to read correctly was pretty much the same among these old GM cars or if it varied from model to model. I don't know why they would want to make them different, but you never know. I emailed them and asked but they won't be in till Monday sometime, and who knows how long it will take them to actually answer, so I figured I could get a quicker response here. You guys are always pretty knowledgeable and helpful. The thing cost $79, so I want to be sure it will work before I plunk down the green. Thanks! The one I found is here https://willcoxcorvette.com/corvette-temperature-sender-72-79-3-8-npt-new
"I intend to live forever, or die trying." - Groucho Marx

"This is an old car, but there's still somethin' about it that gets my heart poundin'. I think it's the lack of brakes." - Red Green

cyber104

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Re: LT1 Swap Temp Sender
« Reply #1 on: April 10, 2018, 06:06:10 AM »
Is there not an adapter available - or am I missing something ?

BubburzTheBandit

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Re: LT1 Swap Temp Sender
« Reply #2 on: April 10, 2018, 10:56:51 AM »
Since it has to go from a bigger thread to a smaller thread, I figured an adapter would make it stick out too far to where the actual sensor part wouldn't be in the flow enough to get a good reading. I've read where other people have considered this and said the same thing, and I've read where other people have actually tried it and some of them said it hits the exhaust manifold. So...
"I intend to live forever, or die trying." - Groucho Marx

"This is an old car, but there's still somethin' about it that gets my heart poundin'. I think it's the lack of brakes." - Red Green

FormTA

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Re: LT1 Swap Temp Sender
« Reply #3 on: April 10, 2018, 11:05:02 AM »
I had the same issues with my LS swap... I ended up drilling and taping the water pump for the huge original sender.... I you or someone does find a sending unit that is close let me know. I remember someone buying a bunch of sending units and testing them all with no luck  finding one that was even close to the original...
79 Trans am 301 (work in progress) LS swap n progress
79 Formula 301 (Work in progress)
67 RS Camaro (Work in progress)
See the recurring theme???

cyber104

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Re: LT1 Swap Temp Sender
« Reply #4 on: April 10, 2018, 11:12:44 AM »
Got it - let us know what you come up with - where there's a will........

Re: LT1 Swap Temp Sender
« Reply #4 on: April 10, 2018, 11:12:44 AM »

BubburzTheBandit

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Re: LT1 Swap Temp Sender
« Reply #5 on: April 10, 2018, 11:28:50 AM »
Well, I'm still waiting for an email from that place as well as researching other possible solutions in the meantime, so if I find another way to get it to work or they get back to me and say that one will work I will definitely let you guys know. Other than that, the car is pretty much done aside from the exhaust and decals, so I wish they would hurry up and answer. They have a technical section on the site, and if I'm understanding it correctly, it looks like the values they have shown SHOULD be close enough (I understand that temp gauges and sending units aren't ever really 100% accurate), but like I said, for $79 I want to be as sure as possible.
"I intend to live forever, or die trying." - Groucho Marx

"This is an old car, but there's still somethin' about it that gets my heart poundin'. I think it's the lack of brakes." - Red Green

Eric78ta

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Re: LT1 Swap Temp Sender
« Reply #6 on: May 08, 2018, 02:14:24 PM »
I did same swap.(97 LT1 into 78 TA). After looking for a sensor with the correct resistance for the 78 guage to fit the head and coming up empty handed I just decided to go with a full Dakota digital setup.

Re: LT1 Swap Temp Sender
« Reply #6 on: May 08, 2018, 02:14:24 PM »
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