Got in a bored out rebuilt 391 FT, so itll be running even hotter thn before, anyone know a good replacement upgrade?

ive been quoted 1500 for a recore of the original, wondering if ther is something better, more efficeient...
or maybe they dont build them like they used too and i should get it recored, just seems expensive......

 

ill be picking it up next week ill post the results on here so everybody knows how it goes

 

Yes they dont make em like they use to. A recore sounds like a great idea and what I would do is it at least a 4 row?? than you should have no problems with an over heating issue. Good luck

 

How do you know it will run hotter if you don't try it. Just curious my 391's run cool with origional radiators..

 

I put this radiator in my 78 F600 361FT from Rock Auto Spectra CU456....I'm down where it's hot too, Palm Springs, CA area...couldn't ask for a better cooler..It's Brass AutoZone can get it too... Autozone C456
and if you wanted to look it up at Rock, It's under 1977 Ford F500 w/330

 

Also,FYI, AutoZone is a little more money, but they offer a life time warranty.

 

Take it to a radiator shop and have it flow tested, then decide on what you want to do.
We used to run 391FT's in F and L series Fords hauling logs out of the woods, lots of slow hard pulling in dust and hot summer temps, seldom did one over heat with original 20-30 year old rad's and some of the 391's where .060 over bored.

 

I ended up getting the recore and now am trying to figure out the plumbing among other things...

There is a vertical line running from base tank (adjacent to trans cooler supply/return lines) to top. I think it goes back into the water pump as a supply line, but am unsure. Could anyone provide a recommendation? The photo attached has the line in question circled in red.

 

Didn't notice the trans cooler lines originally so guessing it has a automatic trans, does it have air brakes, that could be the coolant return from the air compressor.

 

Any chance of entering model and year of truck?

 

YES, ALLISON MT-40. NO AIR COMPRESSOR (HYDRAULIC BRAKES)
1968 BLUE BIRD WANDERLODGE 31'

 

Motor home! ok that's probably the coolant return from the heating system.

 

That's right, its an old bird




Coolant return is correct I believe, as block had two coolant lines that circled up the dash to heaters.

However I don't plan to replace these lines (yet). Just want to start up motor (rebuilt). So thinking I will plug the vertical coolant return line from heater system, and just have the thermostat/radiator supply line and thermostat bypass to water pump (1st picture). There is also a coolant supply niipple on the intake directly behind the water pump/fan mount (2nd picture). Any idea if i can get away with plugging this as well, or should it bypass to the water pump too?

 

The plugged fitting in the first pic should be the heater supply line, plugging it is fine till your ready to plumb the heater.
The circled fitting in the second pic we plug on truck apps that use the high mount fan water pump like you have, the fitting in front of the one circled that's pointing straight up I believe we used for the heater return, not sure what it's used for in your app. The MD and HD trucks we used the FT engines in didn't have that return fitting in the radiator.

 

Going to reply with what I would do. (other than NOT be concerned that there would be overheating) Let's assume, that the person doesn't bore a thin block (didn't sonic check), assemble tight (with anything but factory specs) and the rest of the cooling system is in proper order (seeing the attention to detail on the paint, my guess is you know to use new hoses, pump and CORRECT themostat)!

I would take to ANOTHER shop, have them rot it out, pressure test and if ok use! My answer has nothing to do with "virus" money saving mod - rather that rad it better than ANYTHING you can buy today (looks great) and requires no modification to install.

Mark

P.S. My guess is you are a car guy (have to be to turning wrenches yourself) I treat my C850 differently than my car restorations. I hope you get my reply!