New to site, new to Mopar overheating issues
One issue is that the car is overheating, when it's 90+ here in Kansas.
First noticed the issue when I drove it home after buy it, was running about 3/4 of the way up the temp gauge then got one mark from the H so I pulled over. I tried running the heater but that doesn't seem to help.
It would not hurt to verify the temperature gage is ballpark correct. Even if not, it should have stopped moving up at some point. So it seems safe to say there is a cooling issue.
Since it continued to climb while driving, its not a shroud issue. The electric fan could be blocking some of the airflow at speed. So that's a possible contributor.
Another possibility is the thermostat didn't open. You can remove it and test in a pot of boiling water. Or you can run the engine with the cap off and watch for the surge in flow to the top tank when the t-state opens.
One more possibility to eliminate is a bad cap - ie not keeping the system pressurized.
Electric Fan, on the grill side, that's wired wrong, drawing power from the alternator resistor with no regulator or temp sensor. It wasn't working, I had it running but now there's no power coming from the resistor FLN side now (separate issue) where it was wired into.
I was going to get the stuff to fix the electric fan, but am wondering if I just get the shroud and original setup running right it might be best. Any help would be great, thank you.
Electric fan is not a great idea with the factory wiring and wiring strategy.
As far as going to 'original' there are a couple things to be aware of before trying to buy parts:
The 340 in your car has a water pump with a left side inlet. Before 1970, small block water pumps had a driver's side inlet. The pre-70 water pumps are also shorter.
It looks like a previous owner installed a '70 up style radiator to match the later water pump. That can be OK, but it uses a different shroud than 68-69.
All the suggestions about pulley ratios have merit. if you look in the last pages of the heating/cooling chapter of the service manual there is a table of the various combinatons of fans/shrouds/ water pumps.
