Penthouse Roof Swap. 1990 Chevy to 1990 Chevy.

[Derek]

I'd like to share with you a project I'm working on. First a little back story.

In HS they asked us what we wanted to do after we graduated and I wanted to travel the country, the continent, and the world. I would dream in class of traveling in a van around North America like my father and other family members did. 5 years ago after graduation I bought a 1990 Chevy G10. It was an all original, rust free, southern, garage kept, little lady owned van with full maintenance records and paper work since new. It has just over 200k miles on it but was in impeccable shape. About 8 months after I bought my van my father bought a van as well. A 1990 Chevy G20 Sportsmobile with less than 100k miles on it. Way to one-up me there. However, it was a Canadian van that had sat for a long time and was generally neglected and rough around the edges.

Fast forward to today, my van is still in awesome shape and has been through some slight changes over the past few years although I've mostly figuring out how expensive it is to travel and then how to make money and fund traveling. I've got it figured out though.

That said, the Sportsmobile hasn't faired quite as well. The years of neglect have caught up with it. The windshield frame has rusted to the point water comes in when it rains which the shorts out stuff behind the dash and starts fires. The brakes are simply dangerous, the rockers are toasty, the trans is showing wear and the motor is starting to smoke and coolant is seemingly disappearing. My father also never got into the van thing like he planned and has since bought a nice new truck and a wooden trawler that he loves. Due to the shape of the Sportsmobile he has decided to move it on, however before it goes I convinced him to let me get the roof.

One caveat is that I have to patch the roof on the Sportsmobile so it can still be sold as a complete camper. That resulting in me buying a 1990 Chevy G20 cargo van from a friend that sat for almost two decades. I ultimately stripped all the pats off of it that I wanted, parts out the rest, the chopped the roof off and then cut it in half and scrapped it. For those keeping track, yes, that is three separate 1990 Chevy vans that have come into my life. I haven't had any other van but 1990 Chevy vans. It's honestly kinda weird.

Currently I have just get the canvas sides removed from the sides of the van. Tomorrow if the weather is nice I plan on hopefully at least getting the fiberglass roof panel itself off. I am attaching two photos. One is the Sportsmobile and one is mine. I have been doing as much research as I can on doing the Penthouse swap and I haven't seen anything terrifying, however there isn't a whole lot available. I have been filming the entire process and plan on documenting it somewhat here as well. I also filmed a little bit of a tour of the Sportsmobile before I tore it apart just to kinda show it as it was in it's original state. There doesn't seem to be many third generation Chevy van Sportsmobiles. I think I've seen 3 or 4 including this one.

If a little bit of self promotion is okay I'd like to plug my IG: @automotive_aficionado. The only reason I am is because it has become dedicated to my automotive projects mainly my van and my hotrod and I will post updates there as well. My profile is public so you don't have to follow or anything. If you would like to skip the profile and go straight to just my van then I have hash tagged every single post since I got my van with the hashtag: #DereksVan so you can search just that and it'll bring up every post. Let me know if I should remove this paragraph.

Thanks for looking everyone!

[BenJJ]

Welcome to the forum! I recently installed a poptop on my van, build thread linked below:

http://www.sportsmobileforum.com/for...-19704-11.html

More than willing to answer any questions you have before or during your install. Based on your post, it sounds like you plan to separate the canvas and fiberglass shell. I would avoid doing this if possible. I had to get a new canvas so I didn't have a choice, but there is no real advantage to taking it off unless you have some major repair to do to the fiberglass shell.

[Derek]

Sorry for the confusion. I meant separating the canvas from the roof of the van. I don't plan on removing the canvas from the fiberglass roof until I put a new headliner in it. For now the focus is just getting the roof swapped over.

[Derek]

I got the entire penthouse top removed today. Tomorrow hopefully it will all be on my van. I will make a more elaborate post tomorrow explaining the process.

[BeastGTRV]

Cool low budget project! I like the wheels and sidelights on your white van. Would be cool to backdate it and put the classic 1971-77 van headlights and chrome metal grille on it...so much nicer than the cheap plastic ones they used in the 80s/90s.

Does the rusty Sportsmobile have the interior cabinets, seat/bed gaucho, etc? If you plan to move those things to your van, I would consider swapping the heavy duty 8 lug G20 suspension and brake parts onto your G10. The G10 isn't designed to take much weight (1/2 ton) and would sag the suspension. Perhaps it will be fine, I would keep it in mind tho.

Does the G10 have a v8? Most of those had the 4.3 V6 which is a good engine but a little short on power.

Best of luck with your build!

[Derek]

Originally Posted by BeastGTRV

Cool low budget project! I like the wheels and sidelights on your white van. Would be cool to backdate it and put the classic 1971-77 van headlights and chrome metal grille on it...so much nicer than the cheap plastic ones they used in the 80s/90s.

Does the rusty Sportsmobile have the interior cabinets, seat/bed gaucho, etc? If you plan to move those things to your van, I would consider swapping the heavy duty 8 lug G20 suspension and brake parts onto your G10. The G10 isn't designed to take much weight (1/2 ton) and would sag the suspension. Perhaps it will be fine, I would keep it in mind tho.

Does the G10 have a v8? Most of those had the 4.3 V6 which is a good engine but a little short on power.

Best of luck with your build!

Thanks! I really like the wheels too, I'm not sure if I'm going to keep them though. They're staggered ET Turbo IIs from 1975 that have been restored by Detroit Vintage Wheels. They're the only set in the world and since I plan on really using my van and I just don't want to risk damaging them.

I actually did attempt the early grille swap but the fronts are quite different. To the point of the chrome grille just never fitting right. I attempted to blend the '77 grille and the '90 lower valance panel and I just don't have the skills to pull it off. I wish I had just gone the chrome bezel and billet insert route instead. Someday I'd like to find someone who can graft on the front half of the fenders and radiator support from a '71-'77, and modify the lower part behind the bumper. That would be the only way to make it look correct.

The G10 and G20 are basically the same (at least in 1990). The main differences were the engine like you mentioned and the grille/ chrome bumpers/ trim packages. Mine originally has single headlights with turn signals below them, which was G10 only. The G20 has the 4 headlight grille with turn signals to the side behind the grille. The G30 was the big one with the heavy duty suspension, heavy dude hubs, and could come with the big block or diesel.

Luckily the previous owner upgraded mine to the 305ci 5.0L V8 (G20 motor) and upgraded suspension, as well as a 33 gallon fuel tank which sucks to fill but it great since I don't have to fill it as much. It was used as a carpet cleaner van for all of it's life until I got it so the suspension is pretty worn and rebuilding it all is certainly on the short list of things to do. Ultimately it still drives great albeit a little 'boaty'.

The Sportsmobile does have a full interior with a decent layout. I'm not going to be taking it though. The materials they used is so cheap. It's literally all fiberboard with veneer and this horrible black rubber edging. Over the years it aged poorly and is rough. It was also owned by a smoker so it's got that nasty layer of grime despite our best efforts to clean it. The only cool part is the sofa bed but I plan on having the bed in the back like the more traditional boogie van style and it wouldn't work.

[Derek]

After removing the cabinets and interior trim that was in the way of the tracks I moved onto separating the canvas sides from the metal van roof.

That was easier said than done, although really not that hard. I started by removing all the screws holding the wood to the van roof. It seemed like there were 200 of them. They also were certainly not planned out in any way with the exception of the corners. They were roughly spaced 2 inches apart although sometimes as close as 1/8 of an inch. I imagine one guy with a drill and a box of self tappers just works his way around.

Next with my father on the inside we threaded a piece of smooth wire through the butyl rubber and slowly worked our way around. It was a sort of pulling and sawing motion to get through the stuff. Then every 4-5 inches my father would pound a wooden wedge/ shim (the ones that come in packs of 12 or so) between the canvas and metal roof. It's a slow process and once we got through with it it was almost dark so I put plastic wrap/ shrink wrap/ Saran wrap/ cling wrap/ whatever you want to call it, down between the van roof and canvas then just shut the roof.

[Derek]

The next day I focused on getting the penthouse roof off.

I started by removing the bolts that go through the roof and inner parts that hold the side bars/ cross bars/ lift bars onto the roof. That was not as easy as it should've been because I assume it leaked at some point and someone caulked the entire nut, cap, and large washers to the roof. I ultimately ended up cutting through the caulking and the tops of the caps to expose a severely rusted nut which I would then be able to get at and remove. Luckily I only had one nut that was so rusted the socket wouldn't grab and it came off with vice grips.

After The pads and hardware was removed I had to figure out how to lift the roof slightly to remove the weight from the bars. What I ended up coming up with is what you see in the photo. Two ladders upside down inside the van. The rear one is tied to the door hinges and bumper to stop side to side movement and the front one is tied to the seat base to prevent it from sliding forward and lowering the roof.

We then disconnected and removed the garage door springs in the tracks using a way over-kill but "safety first" *he said whilst supporting the roof with upside down ladders*. I don't think the springs contain anywhere near the '1,000 pound of force' I've seen mentioned. Still, taking a spring to the head wouldn't be good.

Then I removed the side bars. They were held on and together with a seemingly random mix of grade 5 and grade 8 hardware. Them I simply side them out and set them aside. I also removed the other spring that make it "soft close" I think.

Next I removed the tracks. They're held on but another seemingly random mix of grade 5 and grade 8 hardware and it's super straight forward. You just unbolt the hardware and the tracks lift out. They are on the heavier side. The only spacers were two 1/8 thick cuts of chip board at the very front. The rear brace (which I haven't seen anyone else have) was trapped by the ladder.

It was then time to lower the penthouse top. First some personal details. I am 23 years old, 6'5", roughly 320lbs, 'amateur body builder that enjoys pizza' physic. Basically I'm a big dude that can lift really heavy stuff a couple times then I'm done.

I started by loosening the front ladder and sliding it backward which lowered the front of the top some. Then I loosened the rear ladder and lowered the rear of the top some. I then loosened the front ladder and lowered the front as far as I could until that ladder hit the other and then I stood on the couch and pushed the roof up with the top of my back/ shoulders/ head and then wrangled the front ladder out of the way before gently setting the front of the penthouse top of the roof of the van. I then did the same at the back with the rear ladder and now the penthouse roof was sitting on the van.

I can't figure out how to make the photo right side up. I tried rotating it before uploading and it's still messed up. Never mind. I got it

[Derek]

Next it was time to get the penthouse top off the Sportsmobile. We started by me picking up and walking the top backward from the inside. Basically acting as a turtle with the top as my shell. All while taking care to not slice my face against the seemingly cut-out-with-a-butter-knife hole that was behind the tracks and braces.

Once it was at the tipping point we placed one of the ladder to support it as we went until it was just barely on the van. At this point there is myself, my father (65 year old dude who was an industrial electrician and has severely messed up shoulders) and my cousin (21, 6'6", and unbelievably weak; I'm talking loosing the gas cap on his car required considerable effort for him). Basically it on be to support the top while they prevent it and me from falling. I lifted the top up and they removed the ladder, then carefully walked it forward before lowering it down onto the ladders laying on their front/ back to keep the top (and more importantly canvas) slightly off the ground.

I would say the top is in the 260-300 pound range although I have no real idea.
I also forget to mention we removed all the butyl rubber before this step.
Also, anyone else getting tired of the word 'ladder'? I know I am.

[Derek]

Finally with the top removed it was time to take measurements of everything. I also took measurements with the tracks in place as well. I will copy and past all of my measurements here incase anyone wants them. I still haven't measured the overall length of the tracks themselves since I just thought of that now.

All measurements are in inches and sixteenth fractions.
Gutter to outer track flange rear corner right side
9 3/16
Gutter to outer track flange front corner right side
10 13/16
Rear corner to rear cut out right side
58 15/16
Front corner to front cut out right side
26 15/16
Side cut out width with track installed right side
2
Gutter to rear brace left corner
6 9/16
Gutter to rear brace right corner
6 9/16
Gutter to outer track flange rear corner left side
9 7/16
Gutter to outer track flange front corner left side
10 7/16
Rear corner to rear cut out left side
59 3/16
Front corner to front cut out left side
27
Side cut out width track installed left side
2
Track flange length right side
105 15/16
Track flange length left side
105 15/16
Track flange outer to outer distance apart front
47 11/16
Track flange outer to outer distance apart rear
47 11/16
Hole length right side
106 4/16
Cut out start rear from rear right side
58 13/16
Cut out start front from rear
76 5/16
Hole length left side
106 7/16
Cut out start rear from rear left side
59 3/16
Cut out start front from rear left side
79 10/16
Rear left corner hole start from rear gutter
9
Rear left corner hole start from left gutter
10 4/16
Rear right corner hole start from rear gutter
9 4/16
Rear right corner hole start from right gutter
10 4/16
Rear hole width
45 12/16
Front hole width
46
Front hole corner left side from left gutter
11 8/16
Front hole corner right side from right gutter
11 6/16
Cut out width left side
1 14/16
Cut out width right side
1 12/16

Hole size
46x106 6/16

As you can see almost nothing is symmetrical. The hole isn't even close to being centered or square to the van itself and also explains why the top never sat perfectly inline with the van. That won't be the case with my van.

Next it was time to put the roof skin I got from the junk van and have had sitting on top of my van for months onto the Sportsmobile to start the process of filling in the gigantic hole. I tried to get help for this process but after two hours of waiting I just did it myself. Then as soon as I finished they showed up. This is today and as you can tell, I'm still a little salty.

The way I got it swapped over was simply by pulling the Sportsmobile up tight to my van and the sliding the roof skin off the back of my van and onto the from of the Sportsmobile. It was actually really easy and I severely regret not just doing it immediately.

Anyways I digress. I started to layout the cut on my van. I realized that the front-to-rear spacing is easy to determine since it is dictated by the the roof brace just behind the front headliner as thats where the track bolts to at the front. So I started by drilling a few holes just behind the brace so I knew where the from of the cut would be. Then I found my centre line and from that point was able to mark out the first side cut. I won't be marking out the cut out for the bar to slide through first. Once the hole is cut I'll lay the track in place and mark it then is it's precise. U got about done marking the one side when it started to cloud over so I had to pack everything up and tape up a hole from a roof vent in my van that was now exposed since the junk van roof skin wan't covering it. I also threw a couple screws in the roof skin on the Sportsmobiles to hold it in place.

Finishing out the roof and interior on the Sportsmobile will happen in the spring since as soon as I get this roof swap done I'm heading south for the winter.