Have a couple 72 Radiator support questions

[lapedr]

In my 72 assembly manual there are 2 radiator supports 1 for production and 1 for Z28, bg blk, and ac, just wondering what the difference is. I’m thinking it’s the size of the opening but not sure.

Also has anyone cut the area out to make the opening bigger and if you did, did it help to lower the temperature or not make any difference.

 

[roeville]

Yes, the wider opening is for cars that came with HD cooling to accommodate the wider radiator. Most replacement supports I've seen were made to be cut when needed for HD cooling.

 

[CamarosRus]

Another difference that most people miss is the HOLE that the A/C hose passes thru...........

Ive been wanting to learn for YEAR how to replicate this exact hole that is flared to the back side

 

[lapedr]

Thanks so much for the info and pic I think im gonna cut mine out to make it wider

 

[lapedr]

Maybe if you used an exhaust pipe stretcher to flare it out it would look like what you want

 

[70lt1z28]

Another difference that most people miss is the HOLE that the A/C hose passes thru...........

Ive been wanting to learn for YEAR how to replicate this exact hole that is flared to the back sideView attachment 214555View attachment 214557

Easy to copy with a Greenlee hydraulic punch set and which can punch the intial hole and then a custom die that will extrude the flange.

I had to do a version of this on a set of valve covers to pierce and extrude the hole for an old style of push-in breather with the rubber grommet.

For the radiator support, it would have to be a thin wall on one side due to the close proximty to the top edge.

Take it to a local tool and die shop and they should be able to help you. Might be expensive though.

 

[djorgensen3]

Dimple dies will do just what you are looking to do.

 

[berg2695]

Dimple dies are expensive. I'm thrifty (a cheap-ars), so I got an inexpensive panel punch set at Harbor Freight, then made my own dimple dies out of some 1/2 in. high density polyethylene and a router. They worked great on light gauge metal, like the inside of my trunk lid. The lid was rusty, so I separated the two layers to clean and prime, and I thought- why not? The jury is out on whether I will like the look once it's painted. You can make odd shaped dies, too. Sorry about jacking the thread.

 

[CamarosRus]

If "anybody" reading has the ability to loan or rent me the correct looking dies, I will give you ample deposit and pay round trip shipping.

Front of GM hole is NOT flared like holes in above hood....................