'51 Chevy hardtop roof on '50 Olds - has anyone done it?

[ChrisBcritter]

I've seen some excellent fastback conversions using 1/4 of a '51 Chevy and 3/4 of a '50 Olds, but I'd like to try a 2-door hardtop. Have any of you tried this conversion? I figure on cutting everything from the Chevy along the beltline from cowl to the edge of the trunk. What do you think?

[Art Anderson]

Since Chevrolet, Pontiac and the Oldsmobile 88 series for 1950 were all GM A-bodies, it should work!

Art

[Mark]

Measure, measure, and measure again. The bodies should be the same, but the kits were done 35 years apart by different people at competing companies, so their interpretations will likely differ just enough to be frustrating. I was thinking of a Olds Indy 500 pace car convertible, using the '51 Chevy convertible windshield, but haven't compared the two kits yet.

[Yenkocamaro]

If you don't already own one, may I suggest buying a Caliper. Its capable of measuring outside, inside, and depth. Perfect tool for exactly what you are working on. You can measure to see if that roof will fit or not, and allow you to determine how much you will have to add or take off to make it work. I have had mine for 30+ years, and is one of my most valuable tools. Mine is a dial version, while the new ones are digital, and run about $30.00. Good luck with your project.

Lance

Cheers.

[Ace-Garageguy]

Edited December 25, 2014 by Ace-Garageguy

[Art Anderson]

Comparing the two to each other, I would keep the cowl and windshield from the Olds. There's a big difference between the two. If you use the cowl from the Chevy, you'll have fitment problems between the cowl and hood.

Ahh, but GM's convertibles all had a much shorter windshield than did sedans back in those days--AND those early hardtop bodies were nothing more than a convertible body with a fixed steel top welded in place.

Art

[Rob Hall]

MCW makes the hardtop body in resin, by the way...

[ChrisBcritter]

MCW makes the hardtop body in resin, by the way...

Edited December 24, 2014 by ChrisBcritter

[MrObsessive]

That's pretty much the technique I would use. It's similar to what I did on my '59 Impala WIP, when I swapped roofs from a '60.

I did keep the cowl intact though------slightly different from the '59, but oh well.

[ChrisBcritter]

Thank you Roger! It looks pretty straightforward to me. Somebody ambitious would be able to build the Polynesian from this combo (I'm shooting for street/strip circa 1960 with mine).

[ChrisBcritter]

You'll have to school me on the Polynesian.

Best schooling you can get is at kustomrama.com:

http://www.kustomrama.com/index.php?title=Jack_Stewart%27s_1950_Oldsmobile

Nice thing is you can see where the body cuts were made.

[Ace-Garageguy]

And now for another way...

Cut the Chebby like zo...

Cut the Olds to match and drop in the donor roof and tail. You have to match the angles of the donor piece to the tops of the rear of the Olds doors...

Line up the bottom of the beltline chrome of both parts (you will lightly file the top of the AMT donor chrome to match the top of the Olds chrome) and make sure the line of the windows is straight...

Do it right, and you have very little fill work to do, and what there is is in the body crease...to me the easiest place to do it and get clean results.

You WILL have to mildly reshape the leading edge of the roof panel and the corners of the windshield frame. Simple, and if you're careful, the '50 Olds windshield should still fit.

Edited February 9, 2015 by Ace-Garageguy

[Guest]

The only problem with that is now you have a Chevy trunk on the Olds body. There's a big difference between the two.

[Ace-Garageguy]

The only problem with that is now you have a Chevy trunk on the Olds body. There's a big difference between the two.

Yes, the models ARE different.

However, in the real world (and according to the classic Olds forum) some of the decklids interchange. So, both the AMT Chevy and the Revell Olds can't be right. It's up to the builder to decide if staying with the Revell deck style is worth the hassle, and to research whether the real-car post-style decklid is even the same as the hardtop.

From the Classic Oldsmobile forum...

'49-'52 Chev, '49-'52 A body Pontiac, and '49-'51 A body Olds (76 and 88) will interchange to the same body style.

2 and 4 door fast back lids may, or may not, interchange.

2 and 4 door sedan may, or may not, interchange with Holiday (Bel Air and Catalina) and Convertible lids.

Coupes (not to be confused with 2 Door Sedans) are all by themselves

Zo...my guess is that the hardtop GM decklids are the same across the board (Chevy, A-body Olds and Pontiacs). I don't have an old Hollander interchange manual to verify this, however.

Do you?

Edited February 9, 2015 by Ace-Garageguy

[Ace-Garageguy]

OK...I DID find an online GM '49-'66 interchange manual (posted by the Pontiac Club of Phoenix) and the part numbers for the '50 Olds coupe decklid (the Revell kit) and the hardtop / convertible decklids on the real cars are different. The '50 Olds hardtop / convertible decklid part number is the same as the '50 Pontiac hardtop / convertible decklid.

The part number is also different for the Chevy Bel Air (hardtop and convertible), but this could easily be due to different holes in it for trim, different latch attachment, etc.

What this means is that the decklid on the Chevy BelAir I used (AMT kit) for the above swap could very easily be correct (or close to it) as the Olds coupe decklid (Revell kit) IS DIFFERENT from the Olds hardtop / convertible in real life.

The '50 Olds hardtop and the '50 Chevy Bel Air hardtop decklids look pretty similar to me...though the Olds deck looks like it could be a little fatter, more vertical at the rear, this could also be due to camera angle, as the Chebby is shot from a lower position relative to the car.

This is, of course, the kind of thing kit designers are up against when they have only photographs to work from, and no real car for reference.

Edited February 9, 2015 by Ace-Garageguy

[Cool Hand]

Personally if I ever did this conversion, I would do it the way Roger done it. As his method would require no tedious filling and sanding.

[Mark]

I'm surprised the two fit together so well, seeing as how they were created nearly forty years apart, by competing companies, certainly with different personnel, likely with different methods. Having a spare '51 Chevy convertible body with radiused rear wheel openings but a good deck area and windshield frame, I've now got some direction for the '49 Olds convertible pace car that I'd like to do...

[Ace-Garageguy]

Personally if I ever did this conversion, I would do it the way Roger done it. As his method would require no tedious filling and sanding.

If you ever do, be sure to show us your results.

My method avoids having to add styrene to the door tops to get them to line up, and avoids what looks like difficult filling very close to details at the bottom of the rear glass.

My method also puts all the filling in the body crease where it's relatively easy (for me, anyway), and keeps the windshield frame in one piece, which should make it easier to get the windshield to fit.

Your opinion may vary.

Edited February 9, 2015 by Ace-Garageguy

[Ace-Garageguy]

I'm surprised the two fit together so well, seeing as how they were created nearly forty years apart, by competing companies, certainly with different personnel, likely with different methods. Having a spare '51 Chevy convertible body with radiused rear wheel openings but a good deck area and windshield frame, I've now got some direction for the '49 Olds convertible pace car that I'd like to do...

Well, if both companies could measure accurately, and divide by 25 accurately, by whatever means and no matter how many years apart, the two SHOULD fit well. Scale is scale, and apparently both companies did their work quite well...happily for us.

The fastback conversion I did a few years back fit quite well, also.

Edited February 9, 2015 by Ace-Garageguy

[Guest]

The only problem with that is now you have a Chevy trunk on the Olds body. There's a big difference between the two.

Obviously, I need to clarify this statement somewhat. Maybe the following photos will help.

Note how the bulge in the Olds trunk tapers towards the rear creating a transition on the sides where the trunk meets the quarter panels. The transition also widens towards the rear. The AMT trunk has no transition there and is wrong for even the Chevy. When I get around to the Chevy, the trunk will need some reshaping. Also note the difference in the panel below the trunk. The Chevy's is more vertical and has a very slight curve across it. The Olds' panel below the trunk is slightly sloped and much more rounded. To me, the differences between the two are substantial. Some may not notice.

Here's a side by side

Finally, there's the differences in shape at the front of the trunks where they meet the tulip panels. Note the curve at the front corners.

Hope this clears things up a little.

[Ace-Garageguy]

Yes Roger, you're absolutely right about the subtle shape inaccuracies on the sides of the Chevy decklid.

I noticed it when comparing the photos of a 1:1 Bel Air to the AMT model decklid. The re-shaping is very easy and straightforward if done with round files and round sanding blocks...I've already done it...and there is plenty of material in the AMT body casting to allow for the work to be done without excessive thinning.

The decklid cut-line on the AMT Chevy is not symmetrical either, as I'm sure you've noticed.

To clarify MY point... the Olds coupe decklid is different from the Olds hardtop decklid in reality, so just because you keep the Revell decklid doesn't mean you have the correct deck for a hardtop.

I'm fairly certain that a hardtop deck shouldn't extend as far forward as the Revell Club Coupe deck does, but without having 1:1 cars to measure, it's pointless to argue the matter.

Frankly, it's all rather a moot point for me anyway, as I'm building the Olds / Chevy mashup into a '51 Pontiac hardtop...which has the same decklid part number in reality as an Olds hardtop, so the final correction of the Chevy decklid for the Olds will be appropriate for the Pontiac.

I do have access to a real '51 Pontiac fastback, and a '50 Olds club coupe, but no hardtops at this point in time.

Edited February 10, 2015 by Ace-Garageguy

[w451973]

I'm sorry to change the subject but can you guys tell/show me what kind of saw you use to make those nice straght cuts ? I think I want to try this conversion myself after seeing this. Nice work by the way.

[Ace-Garageguy]

I use an X-acto 32 TPI (tooth per inch) razor saw, some photoetched saws, and good ol' #11, 17 and 18 X-acto blades.

I prefer the deeper blades made for the miter-box.

Edited February 12, 2015 by Ace-Garageguy

[w451973]

Thanks Ace. I have to get me one of those.

[Fat Brian]

Another tool I've found indispensable for work like this are the photoetch saws made by The Model Car Garage, they look this this http://www.michtoy.com/HmichtoyTOYsoldier.php?michtoyPROD=michtoy2010/products/Picture_mcg2238.jpg&geurlar=390&teurhau=300

You put them in your #11 Xacto handle and then just saw through the plastic. I just started using them and they are incredible.

Edited February 14, 2015 by Fat Brian