80s front clip change not fitting

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Jarrett Melvin

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Just getting the straight axle swap done on my 87 and I was replacing the front clip with another 80s single square headlight front clip and fenders. But nothing seems to line up.

Was there any differences in front clips/rad supports throughout the 80s, or is it just a matter of adjustments?

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yevgenievich

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Check if using correct core support mount pad things. Otherwise it takes a stack of shims in all the mounting points
 

BKING33

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Sometimes the metal cups can stick. Maybe part of an mount is stuck on bottom of rad support
 

bucket

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Your front cab mounts may be completely shot, which can cause the terrible fitment issue you are having. The old fenders may have been helping to support the cab.
 

Jarrett Melvin

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Your front cab mounts may be completely shot, which can cause the terrible fitment issue you are having. The old fenders may have been helping to support the cab.


The cab floor is soft, I have new floor pans to put in. But maybe moving the truck around the yard and in and out the garage could check let it sink some more.
 

bucket

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The cab floor is soft, I have new floor pans to put in. But maybe moving the truck around the yard and in and out the garage could check let it sink some more.

Yes, it could have. It's normal for the rubber mounts themselves to collapse some and be part of the issue. But if the steel mounts in the floor are failing, it compounds the problem.

The front fenders, when bolted to the cab and core support, become a structural unit. If you were to jack up the front of the cab, install and tighten the fender bolts while everything is aligned, and then remove the jacks, the fenders would hold the cab up.

Was your old core support rotted out too?
 

Jarrett Melvin

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Yes, it could have. It's normal for the rubber mounts themselves to collapse some and be part of the issue. But if the steel mounts in the floor are failing, it compounds the problem.

The front fenders, when bolted to the cab and core support, become a structural unit. If you were to jack up the front of the cab, install and tighten the fender bolts while everything is aligned, and then remove the jacks, the fenders would hold the cab up.

Was your old core support rotted out too?

The wheel wells, support and inside of one fender was rotted out. This is an older support with the bigger single square headlights that I like.

Besides the issues of the cab floors and other factors that's causing the misalignment. Should any other 80s style support be bolt on or were some different?
 

bucket

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The wheel wells, support and inside of one fender was rotted out. This is an older support with the bigger single square headlights that I like.

Besides the issues of the cab floors and other factors that's causing the misalignment. Should any other 80s style support be bolt on or were some different?

All of the front clips interchange as a unit, so that's not your issue. The biggest difference is the '73-'80 front clip with the core support mounts, but that is a front-back fitment issue and not a hight issue.

You clearly have an '81-up frame and any 80's clip is a direct bolt-on. You often have to snug up the core support bolts to get proper door-fender gaps, because of the squish in the bushings. But you have a bigger issue going on.
 

bucket

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If your old core support was rotted out at the mounts, it would have let the fenders sag at the front, if the cab mounts were bad too.
 

Jarrett Melvin

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If your old core support was rotted out at the mounts, it would have let the fenders sag at the front, if the cab mounts were bad too.


Long as I know everything "should" fit or was made to fit. Then I knows it's fixable and I'm just trying to patch something together and make it work.

Thanks again guys, great forum, good for answers to all my questions.
 

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@ bucket,
Wasn't '87 when Gm was going to what I call the "slab side" total truck body change? Maybe the late part of the year '86 they were already changing up how things fit. And maybe they changed where things are on the frame as well. @jerrett Melvin, are you sure you've got a '87? I know that '81 there were a lot of changes mainly to the front, and in '87 they changed the entire truck appearance. Or was that '91???
 

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The new style was 88-91.

The radiator core supports look similar.


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yevgenievich

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@ bucket,
Wasn't '87 when Gm was going to what I call the "slab side" total truck body change? Maybe the late part of the year '86 they were already changing up how things fit. And maybe they changed where things are on the frame as well. @jerrett Melvin, are you sure you've got a '87? I know that '81 there were a lot of changes mainly to the front, and in '87 they changed the entire truck appearance. Or was that '91???
For most trucks change in 88, while crew cabs, blazer, suburban and some other special orders kept until 91 with change for 92 model year
 

Jarrett Melvin

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I pulled the the old rubber floor mats out the other night and discovered the floor plan is cracked about 8-10 inches and the cab mount is 2 inches up through the floor. Id say that's where my miss alignment came from.
 

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