Manifold Heater for Cold Climates

Nigel Hely said
I would connect it, try it, and run it. It can only get as hot as your cooling system will allow, which means temperature should be 'governed' by the thermostat and radiator pressure cap to about 110*C. I live in Australia, on older cars we do occasionally fit a 'heater tap' which is something similar to the item shown in Reply #9 by slantsix64, the purpose being for cars where the heater has water flowing (and heating) at all times, it can be isolated during summer to prevent unwanted escalating cabin temperatures (usually caused by leaking/cracked heater boxes!!!). That said, most of our 60's and 70's models with water-heated inlets flow water continually, with no temperature control. If after trying it, you really think you need 'on the move' control of the heating, look for a cable-operated heater/water control valve off an older model car.

I posted a while back that I was thinking about running my heater hoses , strapped to the runners under side to add a little heat , under my victor intake , which is pretty darn tall.
I got no opinions on it , and havent done it , since I dont drive the fish in really cold weather.
a guy I used to know , had an old jeep gladiator pick up , and rerouted his regulated down fuel line across the top of his radiator , and sealed it w/ factory dumb dumb/putty , he bought from the jeep dealer , it did improve his gas mileage , according to him , which wasnt great on that vehicle to start with. He also had a throttle cable that he would pull out on the hiway for a steady rpm at speed. He would lay down across the seat w/ his feet hanging out the opposite door window, propped up so he could still see , he got a lot of looks from everyone that noticed it .
He died in a wreck on the way moving back to his original home in Alabama , went to to sleep while driving , he was a very good friend !