Too large of a gap between radiator and isolators. What's the fix?

[Polymath]

I put an aluminum radiator in the 85 blazer that was designed for the big block K trucks. I have the proper upper mount and i've made some slight modifications to make sure it fits with the fan shroud and such. I have the correct longer isolator pads. But when I put it all together, the isolator pads don't even touch the radiator. Imagine it like everything is fine but the radiator is a half inch too short. I have been trying to daydream a good solution for this but i'm coming up empty. If I had to guess, the generic radiator is shorter because it lacks the fins that the isolators are normally pressed against. Instead it's just welded aluminum and the bead is where the islolators hit but they aren't tall enough.

 

[mrk5]

Maybe a piece of 1/2" square tube between the isolator and the bracket. Could drill a hole for the little nub on the rubber and another hole opposite to bolt the square tube to the bracket.

 

[HankScorpio]

I put the Amazon big block aluminum radiator in my k5 and it was a good 1/2 short too. I ended up making new upper mounts that use the regular rubber isolators. Drilled a hole for the nub like mrk5 suggested.

 

[Polymath]

Sounds like a good plan to me. Thank you gents!

 

[HankScorpio]

Couldn't find a close up but mounts are shown here. I ground down the pinch weld to make fabbing the mounts easier.

 

[Polymath]

That looks like the same rad I got for sure. The one piece upper mount looks nicer to me so I may stick with adding a 1/2" spacer from square tube. But those mounts do look clean and easy to make after grinding down that pinch weld.

 

[HankScorpio]

I only had some small block mounts, a spacer would have been easier but didn't work with the pieces I had.

 

[Polymath]

I was about to cut up the SBC mounts but then I looked up the cost of the one piece BBC upper mount. It's cheap, so I bought it thinking that would be the end of all the problems. How naive of me.

 

[Wes Harden]

My thinking would be to raise the lower rad bushing cups. would be a simple task to remove cups, make a shim for required filler and tack weld the cups and shims in place.

 

[skunked]

My thinking would be to raise the lower rad bushing cups. would be a simple task to remove cups, make a shim for required filler and tack weld the cups and shims in place.

That’s what I did and it looks OE besides the radiator being AL. @HankScorpio used the same radiator as I did and I’m pretty sure I posted some pics of the bottom spacers I built.

 

[skunked]

Here’s some pics of the spacers I built. IIRC I started with square tube, cut one side off it and drilled holes for the poly mount alignment pin. It’s been like this for a few years now, no issues.

 

[Polymath]

I started out thinking that way but i'm using the mechanical fan so I can't raise the whole shroud up that much before it would hit the blades.

I got a stick of 1/2" square tube yesterday and mocked up a piece but it turned out still too short. Thinking I need 3/4" to allow some squish. Also about to toss the one piece upper mount and make some like HankScorpio's. In the end I think it would be simpler than continuing to hack up the molded fins and upper shroud to get them to fit together and look decent. .