The Best Possible Radiator

[mrein3]

I just remembered. The clutch on my fan went out a couple of years ago. I snapped a picture of the NAPA box so the next guy knew what part to order.

[1972RedNeck]

Originally Posted by mrein3

I too had issues with keeping my engine cool in stop and go traffic. When I bought the truck the PO had installed a 4-blade fan WITHOUT a clutch. I had a 7-blade fan and clutch in my shop - probably off of an a-body as that is the only other Chevrolets I've ever owned. It was the right diameter and was centered perfectly in the shroud. No more cooling issues.

What I would if I was you is:
#1 Ditch the flex fan. As soon as longhornman sees this post he'll post a picture of a hunk of a flex fan blade sticking through the hood of a truck. People have died when those things came apart with the hood open. When I bought my 1971 convertible it had a flex fan on it. That flex fan was on the shop floor within 30 minutes of getting it home. Replace it with a stock 7 blade and stock replacement clutch and don't look back.

#2 Roll around with the 7 blade and clutch for a while and see how things work out.

If your stock fan is centered in the shroud opening and your radiator has decent water flow inside of it you'll be just fine.

Is 7 blades better than 5? I have a 5 blade clutch fan.

[ubtripn]

7 would move more air. Just curious - is there a reason you don't want the clutch? (You asked if they make a fan with the same pitch with no clutch.) Only reason I am asking is because the clutch fan set-up worked so well for me. I pulled one out of a chevy in the wrecking yard for 5 bucks. Its the only component not new. Make sure to get 18 inch diameter though so the shroud works. I a running a 19inch with no shroud but it cools just great.

Try the 5, it will probably work great. Changing them is not hard if it does not.

[Fitz]

Originally Posted by 1972RedNeck

I would like to upgrade the radiator in my '72 K2500. Mine keeps it cool just fine but in city traffic it gets warm. I have a flex fan on it.

My truck currently has a stock 4 core in it. I would like one that fits in my mounts. It needs to be tough, as the gravel roads I drive on are rough.

Is aluminum as sturdy as brass and copper? One thing I would prefer NOT to have is the very fine high efficiency radiator.

All input AND, believe it or not, opinions are appreciated.

When I built my 67 I was concerned about cooling as I went from a smallblock to a large big block which did not leave enough room in front of the engine for the normal fan, clutch and shroud AND I live in Tucson AZ, where temps in June easily reach 110. A BeCool 4 row aluminum rad with two electric fans keep it cool in summer in traffic.