Best radiator for towing 10k

[OkieFishMan]

I'm going to replace my radiator and want to upgrade to something with more cooling capacity to keep the big block happy. Suggestions?

Also, would I be better served going to an electric fan or just replace the fan clutch and keep runnin it? (Yes, electric fan will probably require an upgrade to the alternator and charging system and wiring of the charging system, but that is fine as I plan to do that anyhow)

I'm ordering parts for this build now, with plans to hit the ground running in 18 days. Gonna be fun!

Thanks!

 

[1987 GMC Jimmy]

I'm going to replace my radiator and want to upgrade to something with more cooling capacity to keep the big block happy. Suggestions?

Also, would I be better served going to an electric fan or just replace the fan clutch and keep runnin it? (Yes, electric fan will probably require an upgrade to the alternator and charging system and wiring of the charging system, but that is fine as I plan to do that anyhow)

I'm ordering parts for this build now, with plans to hit the ground running in 18 days. Gonna be fun!

Thanks!

I can't offer any partiality to a certain radiator, but I can say that a fresh heavy duty thermal fan clutch will do you just fine. Also, running a cooler thermostat will help. 180*F would be great. If you have a 195, I don't think it's necessary since you're not running TBI or anything like that. Check your timing, too, and set it at 8-10* initial. More retarded timing produces more heat.

 

[yevgenievich]

The biggest you can upgrade is the extra wide radiator. But need a shroud for it as well.

 

[OkieFishMan]

Yeah, I've just been looking at aftermarket radiators and you can get 2 row aluminum, 2 row aluminum with larger 1.25" tubes, 3 and 4 row copper/brass. I have no idea what would be best.......

 

[CSFJ]

I've heard that the aluminum ones tend to be more effective at cooling, able to cool with fewer cores than the older brass/copper units. I guess if it were me, I'd be shopping build quality over material. I hear a lot about plastic tank failures on replacement units. Either the tank leaks at the seem where it's fastened to the core, or cracks. If you're looking at a performance radiator, where the tanks are aluminum and everything is nicely tig welded together, I wouldn't worry too much. Go with what they would recommend for how you're going to use it. Otherwise, if you can find an all brass and copper unit, you know they'll last a good long time. Just get as many cores as you can get/fit into the application.

 

[74 Shortbed]

I got a couple Champions I've had for a while now and they fit and work great, even in 115* weather.

 

[75Monza]

I really like the aluminum upgrade, definitely cools better. I agree about the plastic tank radiators, nothing but problems, they also don't like any twist if your offroad and getting really twisty. Full welded aluminum tanks is the way to go, just put one in my 86 K20. The down side of this equation is that while I only spent around $160 to buy the radiator on ebay, it is not direct installation. Both hose inlet and outlet were 1 1/2" where my old radiator was 1 1/4" on the top. Had to get a new stock hose, a small exhaust pipe expander, put the expander in the hose and heat it with a heat gun and opened it up to stretch the hose...worked pretty good. Next, the original rubber mounts for the radiator are the wrong size, so after much searching, figured out that if you buy a pair of the large square rubber mounts that you slide over a splitting maul handle (used to save breaking the handle if you smack it on a piece of wood while splitting nasty stuff), you can fab your own mounts. I take one and cut it in half to make two "C" shapes, then carve them with a utility knife till they fit the tank.
Another thing is to make sure you have the radiator shroud in place still, without it very ineffective cooling.
Also, is your truck an Automatic or stick? If Automatic, add a good cooler on the front and make sure you order a radiator with the cooler in it. Loop the lines through, then you have more cooling to keep your trans happy when towing.

 

[foamypirate]

@scottybaccus

I'd have to go against the grain here for the full aluminum recommendation. I have a friend who has been in the hot rod industry for over 20 years, and runs his own shop. They have had nothing but problems with full aluminum radiators. I'll let him explain the details.

On the other hand, I've been running plastic tanked aluminum radiators in my trucks for years, and never had a problem with any of them. I've currently got the Spectra Premium CU730 (big block w/ HD cooling) plastic/aluminum in my LS swapped crew cab. It hasn't missed a beat. The Spectra Premium in my old 84' (now owned by a co-worker) is still running strong 5 years later. Not a weep or seep to be found on either.

Best part? The big block HD CU730 radiator cost a whopping $109 from RockAuto.

 

[75Monza]

Foamypirate does have a point on the con side of all aluminum. You do need to make sure you use de-mineralized water or buy pre-mix to put in it to prevent electrolysis, some even recommend running a ground wire from the frame to contact one of the tanks. Also, I found in winter where I'm at, I end up having to block the grill 3/4" of the way with cardboard or it won't get warm enough for the heater to do squat. And for those in the midwest who deal with salted roads in the winter, they do have outside corrosion issues more so than painted copper radiator. Not sure that you can paint aluminum either without messing with heat transfer ability.
All we used to do before aluminum was get a big 4 core out of a motorhome chassis and put in our big block trucks.

 

[scottybaccus]

That CU730 that foamypirate mentioned is the best buy for the money.

We ditched the all aluminum radiators after experiencing chemical reactions with any coolant mix we tried. It wasn't electrolysis. It was something chemical. Only straight water was OK.
In any case, we are swapping LS motors regularly, and often find 17 and 18 year old plastic tank radiators still going strong, so I think anyone that would turn their nose up at one would have to be dismissive of several million success stories still on the road.

Our preference in a Squarebody is a Spectra Premium CU730, with our Tejas SteelWorks aluminum fan shroud and a pair of 93-97 LT1 Camaro fans. Add an external engine oil cooler and transmission cooler for severe duty. We have customers making up to 540 HP with this setup. Temps stay at about 200*, on a hot summer day, with A/C running, in stop & go traffic. The external cooler we use is a Derale 51608 stacked plate cooler. Running one of these with a 6L80e, behind a Camaro 6.2L, with no converter lock-up, we consistently see transmission temps 15-45 degrees lower than coolant temp. This is the system I'll be installing on my C20 Crew Cab tow pig in the near future.

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These are the Derale plate coolers. They have -8AN fittings, and flow a great deal. None of the clogging issues of the OE coolers.

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