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Radiator Swap Questions

eclipse85k10

eclipse85k10

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Just got my 89 tbi suburban running again and planned to up the radiator but it started leaking so needs replaced now. It always ran on the hot side before and I'd like to do a BB or 6.2 radiator. I should have the brackets and shroud from an old 6.2 project. My question is I can see where on the driver side of the core support the larger radiators bolt to on my burb and how much further to the left the larger radiators extend to but is the extra length in the core its self or the is it in the tank? The opening on the core support is only so big and with a bigger radiator wouldn't be getting anymore air flow though the core so how does the larger radiator help. Seen quite a few people on here running 6.2 radiators.,
 
I'm pretty certain GM's thought was "every bit of coolant helps, if it gets a bit more cooling then that's ok too". The radiator core is what makes the radiator bigger, not the tanks IIRC, since the core support mounts capture the flange where the core ends, that makes sense.

If you think about it, the core support opening looks bigger on the back (radiator) side than it really is...if you look from the front, there is only enough room for the AC condenser, so it's pretty likely the smallest radiator used is about as much air as the core support will flow.

However, I'd surmise that due to drag through the radiator fins, the larger surface area means the fan is likely able to pull larger quantities of air through the radiator with less work, leading to more efficiency.

If your radiator just quit, then it's pretty likely it was not cooling well in the first place. So your overheating MIGHT just be from that fact, or an iffy fan clutch. Never hurts to go large on components, except the cost. From what I've heard, the biggest radiators for the trucks are stupid expensive ($400+), where the AL/plastic "standard tall" radiators are likely ~$150. If cost doesn't matter, then go larger. That stupid expensive price may start getting you into good aftermarket AL radiator territory.
 
I priced out the stock and a big block rad and it was 50 bucks more at 200. Probably was in pretty sad shape I know it's been in there at least 10 years since I've owned it and with this new engine I planned to upgrade it soon before it started leaking out of the tank. I just figured if I'm replacing it now maybe I should go bigger for the hot summers here.
 
The BBC radiators as I recall were not the same as the diesel ones. Perhaps later on they were, but I know the BBC in my dads (with 81+ front end) truck had a "smaller" radiator with the proper BBC shroud.

I know the setup you talk of, with the upper radiator mount way out where the upper edge of the core support starts to slope.
 
Dorian is right, the bbc radiator is the "standard" width and only the diesel radiator is wider.

Fyi, the hose outlets on the diesel radiator are larger than those for a gas application so you'll have to do something about that prior to installation.

I put a 6.2 radiator in my 91 K5 and it works / fit really well. I did have a radiator shop change the top outlet to the size I needed and I found a hose that fit the lower outlet.
 
Is your 91 still a tbi? Did the 6.2 radiator help your Temps? I know larry switched radiators to this one for his 8.1 in his suburban.
Spectra Premium CU774 Complete Radiator for General Motors https://www.amazon.com/dp/B000C7VZTG/ref=cm_sw_r_awd_G8x-vbRGQ3080

I just got the burb running again after a year and a half sitting so if it takes me a bit more time for a cooling fix upgrade I'm ok with that.
 
I have a BB in my 85 and it is 33" wide and 19" tall had to move Charcoal canister out of the way to make room for it. It is not the radiator for the 6,2. Bought it from the dealership.
 
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