The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 67-72 Electric speedo

68c10airstream · 09-09-2015, 08:47 PM

Hi Curt, ls1nova is correct on drilling the head for the original sender. I was reluctant and my water pump has a nice flat boss on the forward area that worked great. As i've stated in prior posts that when i was done my temp gauge read about 3/4 scale as the LS runs hotter than my original 68 small block. Once it was installed and at 3/4 scale i cut the wire close to the sender, temporarily installed a variable resistor and dialed in some additional resistance and dialed the temp gauge back to 1/2 scale. Removed the resistor and read the value. It was 4 ohms, so i soldered in a 4 ohm, 1/2 watt resistor inline. All is good!

09-09-2015, 08:47 PM	#349
68c10airstream Registered User Join Date: Mar 2013 Location: Marquette michigan Posts: 828	Re: 67-72 Electric speedo Hi Curt, ls1nova is correct on drilling the head for the original sender. I was reluctant and my water pump has a nice flat boss on the forward area that worked great. As i've stated in prior posts that when i was done my temp gauge read about 3/4 scale as the LS runs hotter than my original 68 small block. Once it was installed and at 3/4 scale i cut the wire close to the sender, temporarily installed a variable resistor and dialed in some additional resistance and dialed the temp gauge back to 1/2 scale. Removed the resistor and read the value. It was 4 ohms, so i soldered in a 4 ohm, 1/2 watt resistor inline. All is good!