Radiator question

[Rufas]

I have a 1970 GMC 2500. That my parents purchased new in 1970. Five years ago I went completely throught it. It's not a frame off restoration but close.

The engine is a 300 hp 350 SBC crate engine from GM performance. The engine has a small Weiand 142 supercharger, FiTech EFI, original 4 core radiator (great condition) and 700R trans. It's fully bagged with Ridetech 4 link rear suspension.

The truck runs great, no issues at all. Engine temps runs between 179⁰ and 183⁰ while driving. Because of the supercharger I can't run a fan clutch. Belt system is serpentine with a 19 inch 6 blade fan and factory fan shroud. The only issue is when stopped in traffic I get a slow increase in engine temp. Temp will keep climbing until I start moving, then immediately the temps will decrease.

Before I installed the 6 blade fan and shroud I had duel electric fans with shroud. That did not cool as well as the fan blade and shroud.

I've done research here on aluminum radiators but I wondering if going to an aluminum radiator will really help cooling at idle. I really don't want to spend hundreds of dollars on an aluminum radiator and not fix this cooling issue.

Who makes a good aluminum radiator that not going to break my bank account. What brand, type, rows, fin count per inch etc.

Any info is greatly appreciated.

Last photo is how this truck looked in 1970.