Which 4 DR roof?

[khier]

Inspired (or better say re-inspired) by a couple of recent posts I thought again (and will do nothing, as usual) about converting some 1970 GM B-Body kits to four door hardtops. First and foremost model king Bonneville. I could not find any reference of 4DR HT 1970 Bonneville, so maybe I will consider an Executive. The second is AMT 1970 Impala. The third I have in mind is AMT 1970 Wild Cat. 

For these conversions I thought the Wild Cat roof would be probably the best choice. The question is, did all 2DR and 4DR B-Body hardtops share the same roof?

 

Thanks in advance.

[Tom Geiger]

To add a few thoughts...  The Model KIng 1970 Pontiac is a convertible, which means you need to find a roof to add to start your 4 door conversion.  This car was also sold back in 1970 as a 2 door hardtop.  That might be a better starting point if you can find one.  About the same time that Model King released the convertible, a resin caster did copies of the 2 door hardtop.  

1970 Impala -  F&F Resins did a 4 door hardtop many years ago.  Ed Fluck died, but his son Ed Junior took over most of his molds and equipment.  He may be able to pour a copy.  

[khier]

Thanks for the reply.

It seems there is a misunderstanding here. I was thinking about swapping the wild cat roofs for the Impala and Bonneville. For the Wild Cat itself I do not need to swap anything.

And yes, I have a resin copy of the 2DR HT Bonneville. Did the 2DR and 4DR HT share the same roof?

[Art Anderson]

Thanks for the reply.

It seems there is a misunderstanding here. I was thinking about swapping the wild cat roofs for the Impala and Bonneville. For the Wild Cat itself I do not need to swap anything.

And yes, I have a resin copy of the 2DR HT Bonneville. Did the 2DR and 4DR HT share the same roof?

My advice would be to do a Google Image Search for the '70 Bonneville hardtop (this will get you pictures of both 2- and 4dr hardtops, and print off the best, most nearly side-on views that you can find (there are a bunch of them out there, I just looked).  The Buick Wildcat is the same basic body shell (don't be fooled by the lower body sheet metal--that's just a "suit of clothes with different "pleats and wrinkles"), but look at as many pics of a Wildcat as you can find.

I've just done this, and to my eyes, the roof shape is the same, both for Buick Wildcat 2-and 4dr hardtops, and Pontiac Bonneville 2-and-4dr hardtops in 1970.  This is very consistent with GM practice of the time, body sharing between divisions which went all the way back to the middle 1930's.

It's called "research", something you'll find necessary, and I hope satisfying.  When considering factory stock conversions it's part of the game.  Now, the only question would be:  In model form, will the AMT Wildcat roof fit easily on the MPC Bonneville?  That I do not know--both companies were working in 1/25 scale, but there might be some differences in dimensions (that often happened back in the days before CAD), but with some study, perhaps a bit of cutting and correcting, the conversion should be very doable.

Art

Edited November 3, 2015 by Art Anderson
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[Bob Ellis]

I must have a copy of the F&F resin 4dr 70 Impala. It is a hardtop not to be confused with a 4dr sedan with B posts.

I think the rear windows are different?

[Edsel-Dan]

I also have one of the F+F 70 Impala 4dr's

It May have been the Very LAST one Ed jr had!!! 

I am not sure the mold is Up to use anymore the way Ed told me when I was trying to get mine!!

I have had it for several years, and HOPE to do a copy of the 4dr we had back then

Green Metallic with a White Vinyl Roof

Dad Ordered the vinyl added!!!!

 

Yes the F+F is a Hardtop or Pillarless  "Sprort-Sedan" as was ours

I need to check to see if the Buick Wildcat's roof is the same as the Impala 4dr.

 

I know the SS roof of Both AMT's & MPC's hardtops was Different

The Concave (Reverse Curve) rear window vs convex of the 4dr

[Ron Hamilton]

I too have one of F&F's '70 Chevrolet Impala 4-Door Hardtops. I may build it as a companion to my AMT '70 Ford LTD 4-Door Hardtop, down to the same color combination.

[John Goschke]

The short answer is, no, the '69-'70 Wildcat 2-door and 4-door hardtops did not share the same roof stamping. While they are superficially similar, the 4-door roof is longer and has a larger back window opening. The side window openings are different in profile, where the 2-door is shorter in length.

In these photos you can see difference in size between the back windows, the overall length of the roofs, and the different side widow opening profiles. The 2-door hardtop is a true coupe, in the sense that there is less leg room in the rear seat, while the 4-door rear seat leg room is the same, or nearly so, as the 4-door sedan.

 

 

[khier]

Thanks, John, for your comments. Indeed the roofs are not similar. Well, the conversion will not be as trivial as it originally seemed or hoped for. 

[Art Anderson]

Thanks, John, for your comments. Indeed the roofs are not similar. Well, the conversion will not be as trivial as it originally seemed or hoped for. 

The basic lines, however, do appear similar enough that such a conversion should be very possible.  Roofs, just as with any panel on a model car, can be stretched, and rear window shapes can be altered.  Perhaps not a quickie swap, but I suspect it would be perhaps the only starting point.

It's great to have good 3/4 pictures, but a straight-on side view of each car would sure come in handy!

Art

[unclescott58]

Converting a GM two-door hardtop into a four-door hardtop, and get it right, would be beyond my skill levels. GM had money in those days. Even though the full-size Chevys, Pontiacs, Olds 88s, Buick LeSabres and Wildcats are all based on GM's B body platform, it's surprising how many outer body panels were not shared between models. All the four-door hardtop roof panels between the divisions was probably shared on the B bodies back then. And I wouldn't be surprise if the Buick, Olds, and Pontiac two-door hardtop B bodies shared the same roofs. But, with Chevrolet being the big money maker for GM, it not only got its own two-door hardtop roof. It got two different two-hardtop roofs for the Impalas. One called a Sport Coupe. The other called a Custom Coupe.

From 1969 on, the AMT and MPC Impala two-hardtops represented the Custom Coupe version. Before that, the Sport Coupe.

Then we can open up another can of worms. And talk about Buick's Electras, Oldsmobile's Ninety-Eights, and the Cadillacs (other that the post '66 Eldorado). They were built on GM's slightly bigger C body platform. And some years there were variations of C body, referred to as the D body. And before 1959, Chevrolet, Pontiac, and sometimes Oldsmobile used the A body platform. Starting in 1964 the A body would come back. But, not as a full-size car. Now as GM's new intermediate cars. The Chevelle/Malibu, Tempest/LeMans/GTO, F-85/Cutlass, and Special/Skylark.

Confused yet? No? We can go into others. Like fact that Buick's Riviera, Old's Toronado, and Cadilla's (post '66) used the same body platform. The E body. Even though the Toronado and Eldorado were front-wheel drive cars, and the '79 Rivieras were rear-wheel drive. And GM spent the money to give them each their own roofs!

And there are X, Y, G, and other body platforms to muddy waters farther.

[unclescott58]

Note to the above post I mad. And for what ever reason I can edit my posts after a certain point down in them? But, in the second to the last paragraph, dealing with GM E bodies. The sixth sentence should read, "Even though the Toronado and Eldorado were front-wheel drive cars, and the pre '79 Rivieras were rear-wheel drive." I missed the word "pre" in there.

Also for those of you who care. The 1977 and '78 Buick Rivieras were not built on the E body platform. Just for those two years, it was built on a modified B body. It rejoined it's E body brethren, now with front-wheel drive in 1979.