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I have a 73 and have an engine with aluminum heads and the original temperature gauge sending unit is larger than the new heads threaded hole in the drivers side head. I remember seeing posts about how to correct this problem with a sending unit from a later model c3 or something but cant find it also could this adjustable temp gauge resistor from willcox be useful for my problem. https://willcoxcorvette.com/corvette...resistor-68-76 I am using the factory 1973 gauge.
Thanks
Bobby
The factory heads use a 1/2 npt thread and most aftermarket heads use a 3/8 npt thread.You can re-machine the original part,go with the resistor,or possibly install the original unit in the intake manifold.
Hope this helps,
Dave
Last edited by 76strokervette; Dec 7, 2015 at 08:12 PM.
The engine is assembled and in the car already so machine shop isnt going to work out. I actually did think about getting a 3/8 close brass nipple and a 3/8 to 1/2 female brass reducer and doing it that way to use the original sender but didnt know if that wouldn't work for some reason. would that not be a good ideafor some reason?
I re-machined mine to fit the cylinder head.What intake are you using?Many have an extra threaded boss you can install the factory sender in.If you try an adapter you'll have to check the clearance to your headers/ exhaust manifold.
I re-machined mine to fit the cylinder head.What intake are you using?Many have an extra threaded boss you can install the factory sender in.If you try an adapter you'll have to check the clearance to your headers/ exhaust manifold.
Yeah, it only takes a few minutes to increase the thread size to 1/2" NPT and then you're able to use the larger sender.
That looks like a great solution Willcox. However, I have spent way tooooo much money with you guys the last few weeks and going to place another order in a couple days. HAHA
Assuming I have clearance with the headers is there any reason this adapter wouldn't work??
Originally Posted by Willcox Corvette
You'll probably need the adustable resistor to dial in your gauge, but I make a sender that will screw into your 3/8 npt hole.
I don't see any reason why it won't if there is room... That will depend on how deep the npt thread is on the adapter. Has anyone else tried that part for fit, I've not.
Last edited by Willcox Corvette; Dec 8, 2015 at 05:19 PM.
Temperature Sending Unit Thread size question
