RTTOY

With cutting the posts out of the body and doors, replacing the windows and weather-stripping with sport coupe ones can anyone see why this conversion couldn't be possible?

rocketraider

Other than losing all the body reinforcement...

The hardtop and post bodies are very different structurally. If you want a hardtop, go find one. You'll have to destroy a hardtop to get all the components anyway.

Oldsguy

I agree

joe_padavano

First, in Olds-speak, a Sport Coupe IS a post coupe. Holiday Coupe = hardtop. Second, as others have noted, there are internal reinforcements that the hardtop has to replace the posts. The window tracks and regulators are different. The glass is different. The vent windows are different. The roof rails and weatherstripping is different. The interior upholstery is different. Doing this correctly will cost way more money than just selling the Sport Coupe and buying a Holiday Coupe. Also, while certainly not impossible, this has the potential to become one of those projects that results in the car being disassembled and never put back together again. Sorry.

RTTOY

First let me say thanks for the responses.

This particular Cutlass needs a full restoration so replacing interior components is already needed.

As far as the structural comments go I disagree, any hardtop coupe carrys its structual load threw the roof and down the A pillars. Even so I'm sure there have been plenty of "A" body convertible conversions. I can see slamming/holding the doors could be a problem when cutting out the posts. Simple fabrication could be an easy solution to this issue.

Finding the correct window regulators could prove being difficult, but it shouldn't be too bad.

I could live with a post coupe if it does prove to be too much work but it won't be because I'm not capable of doing it, it just won't be worth it. I may be a newbie on here but not to oldsmobiles and fabrication.

Later this year will be a 70' 98 chopped removable hardtop convertible project. That should prove a bit more difficult.

Does anyone have pictures of a gutted 68' holiday coupe?

rocketraider

Didn't someone post some pics of the differences in body structure and reinforcements on here a while back? or was that on ROP?

68Tom

Not sure what you need, but here: https://classicoldsmobile.com/forums...ion-begin.html

I'll be able to get more pics once I get back to AZ next week.

rockethound

i wouldn't do it i think the post coups are cool i've seen alot of fabrication do a guy i worked with took a 57 chevy convertable he found half in the ground cut the lower rusted every thing off the car and cut and peiced 4 door to put replace the lower half that was cut and the put new convertable querters and tones of filler the ca looks good. it took alot of work and money. he offered tho turn mine into a convetable and i said why if i wanted on i would have bought one. anyway it poses a lot of structural issues.

buds68a77

Why take an already rare model of this car and make it one of the pack,
no dis-respect there pack, ever.
When do you see Buick GS posts', GTO posts', Chevelle posts'??

Regards, Bud

joe_padavano

While I still don't think this conversion makes any sense, once again I must point out that rare does not equal valuable. The Pontiac Aztek is rare. The Pacer is rare.

'Nuff said.

csstrux

I wouldn't do it. Use the post for parts. Once you have them both in parts, and sitting side by side the differences are plain as day. I didn't have my crystal ball with me or I would have taken pics. The basic silhouette is the same but structurally they are night and day. to the tune of 300lbs of extra bracing on the hardtop. Joe knows his stuff. I'd listen. Either get yourself a shell, or sell the one you have and get what you want, unless you are a pro, and they will tell you the same thing you are hearing here. You will only open a can of worms. Besides some people prefer the post let them save it.

wmachine

RTTOY, from your other post, you're looking to replicate a W-30, which would be very cool!
Because of that, it would be better to go with the post coupe, and *that* would be extra cool!
Joe, in this case the rarer post coupe *does* have merit for being more desirable. Because the post coupe is lighter, thus faster.
Ironic, but the easiest way to remember the relative weights of models is: "the more metal you see the lighter the car". In other words, the post coupe is the lightest, the hardtop/pillarless/holiday next, with the convertible being the heaviest. The reason is, of course, that the less metal you see, the more hidden structure is needed for overall body integrity.

All else equal on the car, the post coupe would be quicker, so why change?

68Tom

RTTOY, if you decide to make it a coupe, I'm interested in the aluminum trim that goes around the door window frame, B-pillar, and rear 1/4 window. I'm keeping mine a post.

joe_padavano

Yes. I've posted here in the past that Sport Coupes were either stripper F-85s or race cars.

buds68a77

Seems to me, Mr. Joe ain't havin' anything to do with posts.
By the way what big block came in the Pacer again?

Bud

Olds64

That would be a very difficult conversion. Like everyone else said, it would be easier to find what you want instead of modifying and chopping up a perfectly fine Sport Coupe. Ultimately, if you have the fabrication skills to do this then you don't need our advice.

joe_padavano

At the risk of getting off topic, that would be the Randal AMC 401 Gremlins and Pacers. Nice sleepers.

Yes, I know AMC motors didn't have big and small blocks.

Dpj54

But I will say this. Everytime I get stopped for my 69 Cutlass S coupe. People tell me how are of a car that it is