No top since '83, any suggestions what to try and line up first?

[Toro]

On my '72 Blazer, the previous owner removed the top over 30 years ago. It did not come with a top when I bought it. It has rust in the outer floor edges along the weatherstrip flange, and under the seats but the rocker boxes are solid. I'm ready to do rust repairs, and following all the suggestions here, I need to install the top. It's a double-wall top and after placing it on for the first time, everything is close, but not exactly lined up. The front of the top is sitting good along the top of the windshield frame, and it's centered along the bedsides. However, all the mounting holes for the top down the sides and the rear brackets are about 1/4" or 3/8" off the holes in the Blazer. For it to line up, the top needs to go forward. As I mentioned earlier, it looks like it's in the correct position up front.

So, in general, is there a preferred place to start trying to line everything up? Thanks for any suggestions, I've been worried about this since it's been so long since a top has been on it.

[Thealien]

Get all the front bolts in but not tight. Then you need to push the top forward (and possibly push your windshield frame forward a bit). I have used a 2 X 4 across the back and a couple of straps to the seat brackets or whatever solid you have. Slowly push it forward until you get the bolts lined up in the sides. It can be a pain. I have done it by myself but it helps to have another pair of hands and eyes.


Run a thread restorer (not a tap) into the holes in the top before struggling to get bolts started in maybe corroded or damaged threads. I put a bit of never seize on the threads also.

[lks dcvn]

just a thought - it may be a good idea to check on the condition of the body mounts and bolts.

If they are gone/weak - the body will be sag - usually at the b-pillar, which can cause the holes to be 'close' but not accurate.

If this is the first time putting the top on in that long - I would personally do the following:

• check body mounts / bolts - replacing if they are crusty/gone
• consider replacing top/door seals with new press on ones to assure you are lining up with stable seals

[Toro]

Originally Posted by lks dcvn

just a thought - it may be a good idea to check on the condition of the body mounts and bolts.

If they are gone/weak - the body will be sag - usually at the b-pillar, which can cause the holes to be 'close' but not accurate.

If this is the first time putting the top on in that long - I would personally do the following:

• check body mounts / bolts - replacing if they are crusty/gone
• consider replacing top/door seals with new press on ones to assure you are lining up with stable seals

Yes, the body mounts were pretty much shot.., especially the ones towards the back.

I ordered new ones from GMC Pauls and replaced them today. Everything went ok, except for position #2 (right behind the seats). There is a gap between the bottom of the body and the upper cushion, probably about 1/4".

When I removed the factory mounts, there weren't any shims at position #2. The only shims I found were at position #1, and there were two on each side.

Any thoughts? Thanks for the input so far.

[lks dcvn]

*Usually I replace the shims where I have removed them when replacing mounts and I have done alright most of the time.

You note that your rocker boxes are solid - this is one of the key reference metal parts - so that is a great thing to still have intact when you start replacing things.

How do your doors open, close and latch with the new mounts installed (before adding shims behind the seats)?

When the door is closed - how is the gap between the rear of the door and the rear quarter panel? Is it consistent from top to bottom or is the bottom closer than the top - suggesting that the body has some bow in it? The gap you note between the body and the body mount just behind the seats may indicate the body has been flexed a bit.

Before I do my rust repair - I take several steps to prevent things getting out of alignment.

• replace all of the body mounts/bolts if they are shot (you have done this)
• bolt the top on where I am able to - noting which direction the other are 'off' - are they too far back/forward?
• determine where the body needs to be to align holes in top to bedside
• if top appears to be too far forward - body needs to go up in middle and/or seals need checked/replaced. I have used a jack just behind the door to flex the body up to see if this corrects the door gap and top alignment
• if top appears to be too far back - body needs to go down in the middle or new seals need time to 'relax' with top on. This is not usually what I see as weak metal usually drops the truck to a 'V' near the back of the doors.
• once the top is on and bolted into place - then I move to the doors
• check/rebuild door hinges to prevent slop
• replace seals with new in to assure I am aligning with new rubber - several people have installed new seals and it throws off their door alignment so now is the time if you need new seals for the door/front edge of the top
• if I am replacing the doors - I will mount new doors with rebuilt hinges and align to the style line on the bedside (fixed point)
• install/align latch so door shuts correctly before I cut anything out for repair
• once the new door is installed with new/rebuilt hinges and shutting correctly - I drill a small hole in both upper and lower door hinges and into the a-pillar to enable me to use a drill bit to re-install the doors exactly back to the 'aligned state' when I do the outer rocker (last thing usually installed)
• I then start to examine the rust replacement
• Fixing rust isn't fun, but if the truck has all the factory reference points (top bolted on, new mounts/bolts, solid hinges, functional door seals, doors open/shut correctly and align to bedside) before you cut anything - you will have far less headaches when you get done.

Get some pix of the truck, the rust areas, the current door gap where it latches to the bedside, etc. That will be helpful to see how things are shaping up on your truck. Congrats on taking this on.

I have also included a pic taken by another forum member (vtblazer) that highlights the measurements for the door gap on a solid truck, it may be good to see how your numbers compare for reference. It may show where the flex has occurred over time.

[Toro]

Thanks lks, I put the shims back where they were at position #1 when I installed new mounts. Everything pulled down at position #2 when I tightened the mounts. In fact, I posted a specific question about how tight to install the mounts here: https://67-72chevytrucks.com/vboard/...d.php?t=816340

I posted some pictures in that post, hopefully they are correct.

With the mounts in, the top is a lot closer. It probably needs to go about 1/4" or a tad more to be lined up. I think I can get there by loosening and re-aligning the exposed metal mounts that attach to the middle of the windshield frame. Those metal mounts have slotted opening the screws go through that will accommodate so wiggle room. However, I can budge the Phillips head screws that are holding them to the top. I also discovered both captive nuts in the top for sun visor mounts are spinning. Once I get those fixed and the middle mounts loose, hopefully everything on the windshield frame will line up and I can get some bolts started, and then see what the back looks like. I really appreciate all of the info and assistance.