[aronhk_md]

Good to know that diego. We might have to see what we can do as a group.

As for the number of 428 HO with 4 spd convertibles? Just know that its very small most likely because it shares that 205 total # with...

400 4 spd convertibles
400 3 spd convertibles
428 4 spd convertibles
most likely the 428 wasnt available with a 3 spd but its another possibility
428 HO 4 spd convertibles (your car)
I'd lay bucks that the 428 HO WASNT available with a 3 spd. But those are all sharing that 205. At this point its anyone's guess as to how many of each.

[Diego]

I just wrote a whole bunch of stuff and then it disappeared. I'm not going to write it over again! :-)

Anyway, one of the things is that there's a good possibility that a decent amount of HOs were sticks because it was a performance motor that could have been ordered by performance-minded people. Or, you could have a guy who wanted the top motor for his luxo-barge and wanted a luxury-minded tranny to go with it, in that case an automatic.

Visit www.gmheritagecenter.com to see what resources they have. And www.wildaboutcars.com is also a good resource for other stuff.

[aronhk_md]

Kind of the same thing I was saying. But again....still a guess. lol. We'll just have to find out somehow.....its not like the info isnt there. We know it is probably in 2 places.

[ck67goat]

Subscribing to this thread as good info here. Starting resto on a matching 428 HO convertible.

[2+2+3x2]

Here are some numbers that I and some others put together on a car I owned up until a couple of years ago, not saying this is the end all, just some numbers, take it for what it's worth to you. Good luck on your car.

1967 Pontiac Grand Prix convertible, 428HO, 4 speed transmission
February 8, 2014
The following information has been gathered from the following references:
Performance Years web site-http://forums.performanceyears.com/forums/
General Motors Heritage Center-http://www.gmheritagecenter.com/
Pontiac Historic Services, a division of Pontiac Historical Society-http://www.phs-online.com/
Pontiac Motor Division 1967 Engine Production Listing

There are no available records that can tell us how many of these cars were built with these options but thru extrapolation we can get very close, here is how that works.
From the above references we know the following facts:
1. There were 385 428HO engines installed in all “B” body Pontiacs (Bonneville, Grand Prix, Catalina, etc.) that had manual transmissions, 3speed and 4 speed, these carry the “WJ” stamping on the block.
2. There were 42,981 Grand Prix’s built in 1967, 5,856 were convertibles.
3. There were 205 Grand Prix convertibles that came with manual transmission, either 3 or 4 speed and either the 400, 428 or 428HO engine.
4. Of the 5,856 convertibles produced only 6.5% had the 428HO engine and that equals 380 cars and only 205 of those had manual transmissions.
In summary that means that 6.5% of the 205 1967 Grand Prix convertibles with the 428HO “WJ” engine with 4 speed transmission equals only 13.33 units produced. Are these numbers exact, NO, but it’s as close as we can get at this time. This car also came with factory air conditioning, how many of the 13 had that option, no numbers available on that, can’t be many, have you ever seen one?

[MikeNoun]

If this helps at all, the Pontiac Installation Rates document shows the following for 1967 B-Body with the 428 HO :

3-speed syncro = 18
4-speed syncro = 355
Auto = 1,032

Mike

[mr67gp]

Originally Posted by ck67goat

Subscribing to this thread as good info here. Starting resto on a matching 428 HO convertible.

Excellent - auto or ?? Pictures?

My '67 GP convertible was a 400/auto, but will have a 428HO/stick (5 speed) when done. The 428HO engine came from a '68 Bonneville convertible, which was also a pretty rare bird.

[mr67gp]

Originally Posted by MikeNoun

If this helps at all, the Pontiac Installation Rates document shows the following for 1967 B-Body with the 428 HO :

3-speed syncro = 18
4-speed syncro = 355
Auto = 1,032

Mike

This is interesting data. A total of 18 B bodies came with a 428HO and a three gear manual. Would love to see the rest of the options for those cars. Pretty special order.

[incommunicado]

Great thread here, many thanks for the research and fun to revisit.

Mine is close and getting down to fine details. had hoped to get it to Norwalk this year but for many other reasons it's not going to happen.

428, 4 speed with autotemp A/C, PW, PVW, PL, AM/FM, Cruise, hood lamp, trunk lamp, power antenna, power drivers, reclining passenger, tinted windows, 15 X 7 8-lugs with red lines, solid tubular arms with sway bars front and rear, 2 1/2 exhaust, now triple black.

Can anyone recommend a great person to help me finish it up?

[Stuart]

That is a beauty.

[mr67gp]

Originally Posted by incommunicado

Great thread here, many thanks for the research and fun to revisit.

Mine is close and getting down to fine details. had hoped to get it to Norwalk this year but for many other reasons it's not going to happen.

428, 4 speed with autotemp A/C, PW, PVW, PL, AM/FM, Cruise, hood lamp, trunk lamp, power antenna, power drivers, reclining passenger, tinted windows, 15 X 7 8-lugs with red lines, solid tubular arms with sway bars front and rear, 2 1/2 exhaust, now triple black.

Can anyone recommend a great person to help me finish it up?

As I have lamented before, if we were a few hundred miles closer to each other, I would be there helping you out.

[Diego]

Mike and I have gone over a lot of paperwork to some clarity to fellow hobbyists.

But you have to remember that we have done our best to give you hard data. That's why I am not too keen on your extrapolation.

Originally Posted by 2+2+3x2

4. Of the 5,856 convertibles produced only 6.5% had the 428HO engine and that equals 380 cars and only 205 of those had manual transmissions.

Where did you get 6.5%?

Generally, any percentage should only be applied to an aggregate, either for all full-size Pontiacs or for a specific model. Applying a percentage to a smaller sample is statistically incorrect.

So, for example, if 10% of all full-size Pontiacs had an option like power windows (I just made this up for the sake of example), it would be statistically incorrect to suggest 10% of Grand Prixs had this option. The 10% can only be applied to total production.

Likewise, if 20% of Grand Prixs had 8-lugs (again, making this up), the percentage cannot be applied to convertibles to derive a number.

[STEELCITYFIREBIRD]

So I looked at a 67 GP Convertible 400 Auto for sale today. Can anyone cypher this tag for me?

[johnta1]

Here is what I think:


Convertible


W - tinted windshield

2K - air conditioning
2Z - TH 400

4F - remote control mirror

5Y - custom seat belts



07B - build date


C-1 White with White? top


583 - B : don't have a GP trim codes B is buckets I think


2-43-? is the gang carrier #, or body carrier #

[STEELCITYFIREBIRD]

Thanks!
Has pristine 8 bolt wheels.Factory 8 track.
I guess the exterior color is not correct, but the top is white. Interior is black buckets w/console.
Truly is a nice clean and mechanically sound car just needs some details taken care of.
What are these cars worth?

[ck67goat]

Originally Posted by STEELCITYFIREBIRD

Thanks!
Has pristine 8 bolt wheels.Factory 8 track.
I guess the exterior color is not correct, but the top is white. Interior is black buckets w/console.
Truly is a nice clean and mechanically sound car just needs some details taken care of.
What are these cars worth?

Just wondering - did you ever buy that car? I've been looking like crazy for a decent car simply to use as a guide to restore mine because I acquired mine in parts. There are about half a dozen GPs out there are overpriced - I say overpriced because they've sat on the market for many years with no sale - seems seller not interested in really selling. Problem is other sellers see these and instantly think GPs are worth lots of $$$. There is a triple black convertible I saw years ago at a Pontiac show in IL and the owner won first place at the show - it truly was a top notch resto and it's been up for sale for the last 7 or 8 years. None of the other GPs I have seen out there even come close to that triple black convert in terms of quality but everyone seems to think there's is worth that much so they just sit on the market.

[ck67goat]

Originally Posted by mr67gp

Excellent - auto or ?? Pictures?

My '67 GP convertible was a 400/auto, but will have a 428HO/stick (5 speed) when done. The 428HO engine came from a '68 Bonneville convertible, which was also a pretty rare bird.

It is an auto. It is currently still just a shell so no pictures worth posting yet.

[ck67goat]

Originally Posted by incommunicado

Great thread here, many thanks for the research and fun to revisit.

Mine is close and getting down to fine details. had hoped to get it to Norwalk this year but for many other reasons it's not going to happen.

428, 4 speed with autotemp A/C, PW, PVW, PL, AM/FM, Cruise, hood lamp, trunk lamp, power antenna, power drivers, reclining passenger, tinted windows, 15 X 7 8-lugs with red lines, solid tubular arms with sway bars front and rear, 2 1/2 exhaust, now triple black.

Can anyone recommend a great person to help me finish it up?

Where in Indiana are you located and what kind of help did you need?

[Baron Von Zeppelin]

I thought the HO wasn't available with AC when with a stick?

In some years that is true about the Big Engine HO [421-428] / 4spd /AC exclusion.
In 67 , looks like the only exclusion involved with the 428-HO is
No Station Wagons - zilch .

No idea why, but that is the only limitation.
All previous years with 421-HO , you could get Wagons with HO.



This car was 428-HO / 4spd / AC / Posi / Disc Brakes / etc....

Also look in lower right corner at 428-HO option box
NA on STA. WGN.

just adding to the data pool - fwiw