Blazer rust tips (floor/rocker boxes)

[Bagd72Chevy]

This is kind of my thoughts, if you guys could help me understand the order of work I would appreciate it. I'm going to help my buddy fix his 1972 Blazer. Someone cut the rocker boxes off and never put back. Rockers are new but not done right. Rear floor is bad. Bedsides are good with small spots that are easily fixable. Tailgate is good, have rust free doors and fenders for it.

Replace:

Rear Cargo Floor
Rocker Boxes
Rockers

Unsure at this moment whether I will repair or bulk replace the front floor section. Any input on where to draw the line were replacing the whole thing is better than patching?

My plan is to remove the rockers, bed sides, cargo floor, what's left of rocker boxes.

What order should it go back together? I've done trucks and burbs but haven't messed with a rocker box before. Is the rocker box also the inner rocker?

Thanks guys,
Ryan

[lks dcvn]

Before you change anything - you are going to have to do some pre-work to make sure you don't have issues down the road

• If it doesn't have the hard top on - bolt that on first to get structure to the truck
• Check all the rubber body mounts and bolts - if they are gone or rusted - you will need to replace those as well before you do anything taking note of where the factory shims are at each body mount. Top and body mounts will get you in a way better spot before you start cutting.
• With top and new body mounts - check the doors to make sure they open/close as they should without sticking - shim as needed
• Once I had everything lined up and took measurements at a few key spots (windshield frame to bedside, etc.). I then took the top back off and re-measured to confirm my gaps had not changed.
• You don't have to remove the rear bedsides if you don't have to - the cargo floor is bolted in with tack welds in a few spots near the tailgate. A handful of people have cut out the old cargo floor, spread the rear quarters and slid in the new floor with an extra set of hands. The B-pillar metal has enough flex to do this w/o damaging the quarter.
• The torsion boxes (rocker boxes you refer to) bolt in at the B-pillar to hold the cargo floor in place, and then are welded in at the front at the firewall - this piece is the key structural part of the blazer when the top is off. I'll imagine you will have some other parts needing replaced under there once you dig in a bit. The ones on the truck I repaired were solid so they helped keep the truck aligned with the top off.

The line that tells people to fix a panel or replace a panel - is all over the place. Some will say - ' keep as much original metal as possible' others will say that 'it's easier to just swap in a new panel' - it really comes down to your talent, patience and budget.

I just swapped the entire back half of a blazer over a few weeks this past summer. It was very educational to see how these things are built and to note where rust is hiding. I took measurements from the old bedsides and then drilled equivalent holes in the new bedsides and put the top back on without any issues and the doors open/shut like they did before.

Rocker box is not the same as inner rocker. The inner rocker is an extension of the cab floor and is usually rusted out if your floors/rockers are rusted.

Going back together order that I used:

support brackets for floor/rocker (torsion) boxes
rear cargo floor
wheel tubs
bedsides
outer rocker - this will take some time to adjust before the doors line up so don't finish weld this piece in until you confirm you are lined up.

Get some pix of the truck and several on here can tell you what you are going up against.

Here are a few helpful links to get you started.
Door Frame Measurement links - check these before you cut anything - especially this post.
Parts list I shared with another board member when he was building a blazer.
Build posts have a wealth of knowledge and in the past few years, the aftermarket panels have surfaced making this job a bit easier.

[lks dcvn]

Truck was back together in 3 weeks with me doing the work on nights and weekends when I had the time.

It's all fixable depending on the interest and money.

[Skymortar]

Originally Posted by lks dcvn

Truck was back together in 3 weeks with me doing the work on nights and weekends when I had the time.

It's all fixable depending on the interest and money.

Thank you so much for this post.As soon as gmc Paul's gets the complete front floors in stock I will be replacing from the front floor back.Im a painter at a collision shop so I'm confident we would figure it out but this is EXTREMELY helpful.Thanks again

[Bagd72Chevy]

Thanks for the reply. We just got the blazer stripped down to the body. The front frame horns are tweaked so I'll get it on the frame machine to pull that back over. The front floor is gone and someone torched the torsion boxes off. Inner Rockers are gone. Looking like a whole floor replacement front to back will be in order. I'm planning to cleco the weld seams to get it fitup and then disassemble back to where I can weld it up. Hoping to use my pro-spot as much as possible. If no one can tell I did any work that would be perfect.

[Skymortar]

Hoping to use my pro-spot as much as possible. If no one can tell I did any work that would be perfect.[/QUOTE]



I was staring at my blazer today figuring out where the pro spot will get to

[Bagd72Chevy]

So it gets worse. I took the body off the frame to address the chassis first and the frame is diamond, bent, cracked and hacked. So we are looking for another chassis at this point.

The good is between the factory frame drawings and what's left of this chassis I drafted up a body jig that I can mount to my chassis table to help align everything. After rust repair I will use the body jig to mount the body to my rotisserie. I also picked up a 71 Blazer for myself so I can do the metal work on it using the jig after the 72 is off it.

As of right now we will be getting the chassis lined up and then ordering the replacement floors and patch panels.

Since I don't have much left can you guys fill me in on what panels I need to purchase to do a complete floor. Do I need the cab to bed transition piece if I'm buying complete cab and bed floors?

Thanks,
Ryan

[lks dcvn]

if you buy the complete floors - you will still likely need patches.

front floor
might need the bucket seat braces for under the front floor
rear cargo floor
yes - you will need the step up plate as it doesn't come with the floors
A-pillar - lower patches
kick panels
torsion boxes
outer rockers

get some pix of what is left and we can tell you more details.

Good Luck!

[Bagd72Chevy]

Well we are getting started. Some parts were backordered but finally have it all. GMC Pauls is where I sourced everything. I took a spare chassis and set it up on my frame table so it is flat and square. For some reason one of the bed mount pairs is too short. Everything else lines up. Still thinking about how I'm going to line up the cowl.

[lks dcvn]

Congrats on getting to this point - it's really not that bad once you get all the parts you need.

Some additional thoughts now that you are getting under way.

• use a thread chaser on all holes before you start - some of mine were not clean threads and I wish I would have done it before bolting anything together - I picked a set up at Summit and used it once I found a few issues
• anti-seize is also your friend during assembly as you will take it apart a few times to get everything lined up
• if you are restoring factory bolts - I would clean the thread on those as well to be safe
• you will want to install the 'cargo floor' step up piece before you put on the bedsides as you won't have access to install it once they are in place.
• I did need to bend/push/adjust my panels to get everything in to place - including expanding some existing holes (not visible) when panels are in place
• my gaps are not perfect yet - all parts open close/latch as they should with no binding/sticking (I'm driving the hell out of this thing just so I can enjoy it

Looks like a great start. Good luck!

*Added an 'after' picture of my project (same truck from my post above) for inspiration*

Can you share more details on your issue with the 'bed mount' pairs being too short?

[Bagd72Chevy]

Yes, I have that panel sitting in place now. Need to punch the holes in it for the welds and then screw it together for fitup.

[Bagd72Chevy]

I also have my other body that is in much better shape but still needs alot of work. But at least enough is there to look at how this one should go together.

[lks dcvn]

Very cool! It took me 3 weeks to do the rear half and then 12 more months to do all the rest (floors, inner rockers, supports, a-pillar, torsion boxes, etc.) between waiting on parts, waiting for a free evening/weekend, etc.

I still have to fix the panel gaps and finish weld in the outer rockers to be complete. I'm not in a rush though since I can drive it again now.

[Bagd72Chevy]

The pro-spot is acting up so I jumped on it with the Roper Hole punch. Getting it all mocked up so I can fit everything.


Also threw the bedsides on. They don't fit the floor real well so I'll have top dig into what the issues are later this week. My helper was doing a great job dropping the bolts in.

[jaros44sr]

Looks good so far, nice way to start with all new sheet metal

[Bagd72Chevy]

Making some progress.

[jerry moss]

you are doing an awesome job and your shop is over the top too.

[jaros44sr]

Originally Posted by jerry moss

you are doing an awesome job and your shop is over the top too.

X2 any progress photos good detail on the build thread