Can someone teach me about radiators and what will fit?

[Lgarretto]

That isn't bad. 285 plus whatever for an electric fan. Just having to trim the shroud isn't a big deal at all

 

[Curt]

https://www.gmt400.com/posts/1116564/

I installed a 454SS radiator in my 1500 suburban. It was a direct fit with no modifications needed.

 

[TechNova]

I have been buying from Engineered Cooling Products for my old cars.
Wider tubes are better then the factory sized tubes.
http://www.speedcooling.com/Chevy-Truck/?page=2

 

[JWOK]

You have been given some good advice so far, make sure to narrow down your problem before throwing money at it. When you changed the t-stat did you look in the radiator to see if the coolant tubes were clogged with corrosion or other debris? Have you checked between the radiator and condenser for fins plugged with dirt, leaves, etc. You say the fan clutch is good, do you feel considerable resistance to turning the fan after you warm up the engine and shut it off? Also, a leaking cap is bad news, the system must be able to build pressure as this raises the boiling point of the coolant. Another uncommon possibility is worn down impeller blades inside the water pump, but that doesn’t happen too often.

 

[JWOK]

An easy way to find a larger capacity radiator that will fit your truck is to look through the parts store online catalogs and see what is listed for the various models of the year you have. Example 1500 5.7 may have multiple options listed or compare to a larger 3500 5.7 or 454. Measure your current core height/width and stick with that size to see what core depth options are available. Likely something like 1.25” vs 2.25” depth. This often means they move from a single 1.25” tube to a double 1” or something along those lines. If you currently have the 1.25”, you should be able to find a 2.25” that drops right in. Just make sure to visit the parts store and verify measurements and connection size/location before buying. This is often the cheaper route to increased cooling.

 

[RichLo]

2-row aluminum radiators actually cool better than 3-row aluminum. Please read the link before buying a 'performance' radiator

https://www.speedcooling.com/blog/category/radiators/3-row

 

[PlayingWithTBI]

2-row aluminum radiators actually cool better than 3-row aluminum.

That's probably true if they're the same total depth. It's all about net surface area where the coolant can be cooled by the air passing through the core. Part of that surface area is the side of the tubes too, so a 3 row will have more surface area on the sides and, possibly, being thicker than a 2-row will cool better. Pure aluminum is a better heat sink than copper or brass but is too soft so, they add different percentages of iron, lead, copper, silicon, magnesium, and manganese (among others) to achieve appropriate alloy properties. If I had to guess these radiators are made out of 6060 or 6063 alloy. Faster to extrude and easier to bend than alloys like 6105 and 6061. 7000 series is considered "Aircraft alloys" and it's used in baseball bats too, ha ha.

OK, I'm gonna get off my soap box now, pour myself some tequila, get ready to BBQ a couple steaks and chill a bottle of red wine.

 

[351FUN]

Also I don't think I have a blown head gasket. I haven't done a compression test but there's no froth. No milky oil. I probably need a new radiator cap at the very least. It blows coolant out of the cap pin every time I drive the truck

This needs to be the first thing you fix tbh

 

[Stuckinkali]

Have you checked your fan clutch at higher RPMs after warmup? I've seen even new clutches not function properly following warmup and they don't lock on thermal conditions due to a bad spring. Something else you may want to do is look at your plugs and see if you don't have an overly lean/rich condition. I'm assuming you are running TBI... you may be looking in the wrong area for cooling. As mentioned above by Erik The Awful, get rid of that 160° stat and put the 180°/195° back in. The engines need the correct PCM factory temp to be in the sweet spot (OBDI) for all circuits to function properly. You may need to change out your coolant temp sending sensor/switch too... Just a few more areas to look at. Read your plugs after a good pass at the RPMs you're experiencing the overheating at. It may give you more than you have for evidence on where to start, rather than just putting a bandaid on a bleeding artery...

 

[Stuckinkali]

Also, do you have A/C? You may want to check between the condenser (A/C radiator) and the radiator to see if there's a bunch of crap lodged in there from years of driving... Found many a cooling problem just cleaning that area out to start (assuming you have yet to remove the radiator...)

Good luck