#1  
Old 07-13-2011, 09:22 AM
ramairformula74 ramairformula74 is offline
Senior Member
 
Join Date: Aug 2002
Location: williamsport,pa
Posts: 178
Default Core Support Bars question

I have a set of core support bars from a 1974. I know they are the same as 1975. The question is, are they the same for 1973 or are they shorter or longer? I've seen the repros in catalogs and they fit 73-75. I'm sure some will think this is a stupid question but a possible sale of my original GM bars is why I ask. The potential buyer thinks that 1973 are different. Any help would be great. Thanks in advance.

__________________
1972 GTO, Lucerne Blue, M22 Rockcrusher. 1974 Ram Air Formula 400,4spd,3.42 posi,honeycombs,much more.Rare Bird(sold). 2005 GTO Midnight Blue 6spd( sold).
  #2  
Old 07-13-2011, 10:56 AM
Dens71TA's Avatar
Dens71TA Dens71TA is offline
Ultimate Warrior
 
Join Date: Jul 2002
Location: Midwest
Posts: 2,315
Default

They are shorter than the '73s. 1973 has a large rubber bushing at the top that the bar bolts to.

  #3  
Old 07-14-2011, 12:49 AM
charles bledsoe's Avatar
charles bledsoe charles bledsoe is offline
Ultimate Warrior
 
Join Date: Dec 2006
Location: Flintville TN
Posts: 1,678
Default

How about the 76? Were they like the 75 or like the 78 & 79?
Thanks

__________________
1966 GTO Vert automatic.
1969 CR Judge Ram Air III 4sp Pattern Car.
1969 GTO standard 350HP TH-400.
2006 GTO Phantom Black 6spd.
1972 Formula 455HO Ram Air.
1976 LE Trans Am 50th Anniversary Edition with T top.
1976 Formula 350.
1977 Grand Prix Model J 350.
1978 Trans am 400 Pontiac.
1979 Trans am 403 Olds.
1968 Olds 442.
1971 TR6.
  #4  
Old 07-14-2011, 07:00 AM
superdutybob's Avatar
superdutybob superdutybob is offline
Ultimate Warrior
 
Join Date: Nov 2003
Location: Brighton, MI
Posts: 2,269
Default

The 76 cars that had these bars were like the 74-75 bars. Later cars did not have any bars at all.

__________________
Bob Woodard
Brighton, MI

2012 SRT8 Charger - 12.70 @ 111mph
  #5  
Old 07-14-2011, 12:08 PM
Rack776's Avatar
Rack776 Rack776 is offline
Chief Ponti-yacker
 
Join Date: Mar 2007
Location: Eastern Pennsylvania
Posts: 516
Default

Quote:
Originally Posted by superdutybob View Post
The 76 cars that had these bars were like the 74-75 bars. Later cars did not have any bars at all.
I thought 76 had no bars at all and 77-81 had the thiner flimsy bars.
I had 2 76 parts cars and neither had any evidence of a bar being screwed to the core support.

__________________
Jason Rackawack
1975 455 Trans Am - 1975 Firebird 400
  #6  
Old 07-14-2011, 01:33 PM
superdutybob's Avatar
superdutybob superdutybob is offline
Ultimate Warrior
 
Join Date: Nov 2003
Location: Brighton, MI
Posts: 2,269
Talking

Quote:
Originally Posted by Rack776 View Post
I thought 76 had no bars at all and 77-81 had the thiner flimsy bars.
I had 2 76 parts cars and neither had any evidence of a bar being screwed to the core support.
That's what I said!

76 cars that had bars had them like the 74-75 bars. Later 76 cars got no bars at all, like you saw on your parts cars. After 76, all cars got the thin bars.

__________________
Bob Woodard
Brighton, MI

2012 SRT8 Charger - 12.70 @ 111mph
  #7  
Old 07-14-2011, 02:16 PM
Rack776's Avatar
Rack776 Rack776 is offline
Chief Ponti-yacker
 
Join Date: Mar 2007
Location: Eastern Pennsylvania
Posts: 516
Default

Quote:
Originally Posted by superdutybob View Post
That's what I said!

76 cars that had bars had them like the 74-75 bars. Later 76 cars got no bars at all, like you saw on your parts cars. After 76, all cars got the thin bars.
Aghhhh!, no need to shout!
I missed the "Late & Early" part of 1976 cars.

Thanks for the correction!

__________________
Jason Rackawack
1975 455 Trans Am - 1975 Firebird 400
  #8  
Old 07-14-2011, 07:41 PM
1971WARBIRD's Avatar
1971WARBIRD 1971WARBIRD is offline
Ultimate Warrior
 
Join Date: Nov 2006
Location: Troy, Ohio
Posts: 2,467
Default

i have found several different bars over the years. in 73 there were 2 bars, both long but thinner bars on the formulas and firebirds. same for the 74-76 with bars. the Trans Am's had thicker bars with the formula's having thinner ones. even then i think the 75 was thinner than the 74?? it has been awhile since i looked at a set side by side. i know the 73-74 were thicker as the plastic air duct piece had a wider bracket to fit it.

just a guess, but i think the formula's ordered with the TA suspenion probably got the thicker bars??

__________________
FREEDOM ISN'T FREE
BUT WORTH FIGHTING FOR
  #9  
Old 07-19-2011, 12:17 PM
dadsformula dadsformula is offline
Senior Chief
 
Join Date: Nov 2007
Location: N.E. PA
Posts: 363
Default

71 Warbird, can you advise any more detail on the Thick vs Thin Bars for
73 and 74. My 73 has what i think are the originals, but would like to
confirm. Also my car does have the factory Trans-Am (Y99) suspension.

  #10  
Old 07-20-2011, 08:22 AM
Larry Navarro's Avatar
Larry Navarro Larry Navarro is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Spring(Houston) Tx. USA
Posts: 6,369
Default

I fabbed a few sets of those bars from bars stock aluminum. I used the '74 bars as a pattern. I think i have a couple of sets if someone wants to buy for a trick look or paint them for stock appearance.
Attached Thumbnails
Click image for larger version

Name:	image003.jpg
Views:	214
Size:	74.1 KB
ID:	250489  

__________________
Home of WFO Hyperformance Shaker induction.
  #11  
Old 07-20-2011, 03:35 PM
1971WARBIRD's Avatar
1971WARBIRD 1971WARBIRD is offline
Ultimate Warrior
 
Join Date: Nov 2006
Location: Troy, Ohio
Posts: 2,467
Default

Quote:
Originally Posted by dadsformula View Post
71 Warbird, can you advise any more detail on the Thick vs Thin Bars for
73 and 74. My 73 has what i think are the originals, but would like to
confirm. Also my car does have the factory Trans-Am (Y99) suspension.
i hope someone else jumps in here. i'm not at home to take any pictures of the ones i have, and memory being what it is can't give exact sizes.

__________________
FREEDOM ISN'T FREE
BUT WORTH FIGHTING FOR
  #12  
Old 07-21-2011, 07:18 AM
superdutybob's Avatar
superdutybob superdutybob is offline
Ultimate Warrior
 
Join Date: Nov 2003
Location: Brighton, MI
Posts: 2,269
Cool

I believe that the 73-74 bars are the same thickness, with the 73 bars being a tad longer to reach out to the forward bushing. The 75 bars were thinned down versions of the 74 bars.

__________________
Bob Woodard
Brighton, MI

2012 SRT8 Charger - 12.70 @ 111mph
  #13  
Old 07-21-2011, 09:35 AM
ramairformula74 ramairformula74 is offline
Senior Member
 
Join Date: Aug 2002
Location: williamsport,pa
Posts: 178
Default

I see that the bars are reproduced and say they'll fit 73 to 75. Do you think they were made with extra holes to fit all three years?

__________________
1972 GTO, Lucerne Blue, M22 Rockcrusher. 1974 Ram Air Formula 400,4spd,3.42 posi,honeycombs,much more.Rare Bird(sold). 2005 GTO Midnight Blue 6spd( sold).
  #14  
Old 07-21-2011, 01:08 PM
dadsformula dadsformula is offline
Senior Chief
 
Join Date: Nov 2007
Location: N.E. PA
Posts: 363
Default

73 is the only year for the longer Bars with the big hole for the Top bushing
mount. Not an easy part to find if missing. Ask me how i know. I have
not heard that different Bars were used based on engine size.

  #15  
Old 07-21-2011, 09:07 PM
Held for Ransom's Avatar
Held for Ransom Held for Ransom is offline
Ultimate Warrior
 
Join Date: Mar 2000
Posts: 8,912
Default

My findings...
1973 Formula (Mar), .316" thick
1974 Formula (Oct), .253" thick
1974 Formula (Nov), .310" thick (not pictured)
1974 Formula (Feb), .195" thick
Attached Thumbnails
Click image for larger version

Name:	7374Braces.jpg
Views:	201
Size:	35.2 KB
ID:	250717  

  #16  
Old 07-22-2011, 05:07 PM
SD73's Avatar
SD73 SD73 is offline
Ultimate Warrior
 
Join Date: Dec 2004
Location: SoCal
Posts: 2,061
Default

Quote:
Originally Posted by Held for Ransom View Post
My findings...
1973 Formula (Mar), .316" thick
1974 Formula (Oct), .253" thick
1974 Formula (Nov), .310" thick (not pictured)
1974 Formula (Feb), .195" thick
On a lark, I measured mine for a '73 T/A and got .316 or 5/16th too.

  #17  
Old 07-22-2011, 07:31 PM
Held for Ransom's Avatar
Held for Ransom Held for Ransom is offline
Ultimate Warrior
 
Join Date: Mar 2000
Posts: 8,912
Default

According to the assembly manuals,
1973 PNs were 489182 and 489183.
1974 PNs were 493457 and 493358. And was changed to 496803 and 496358 on 10/12/73. Who knows when stock was depleted (or pulled) and new bars started to be used.

  #18  
Old 07-27-2011, 12:13 PM
Rack776's Avatar
Rack776 Rack776 is offline
Chief Ponti-yacker
 
Join Date: Mar 2007
Location: Eastern Pennsylvania
Posts: 516
Default

The thicker bars might have been part of the 73 crash standards they had to meet,
once the 75-75 bumper was used they might have used a thinner bars to save some weight/cost.

The 74-75 front "battering ram" ....I mean bumper is stronger than the 73 set up so the fender bars were less important in a crash and the extra weight went into the bumper bar.

Just my opinion. Good catch on the different thickness bars.

__________________
Jason Rackawack
1975 455 Trans Am - 1975 Firebird 400
  #19  
Old 07-28-2011, 12:25 PM
dadsformula dadsformula is offline
Senior Chief
 
Join Date: Nov 2007
Location: N.E. PA
Posts: 363
Default

74/75 "Battering Ram" (nice description) i have no doupt is stronger, because
it was a full redesign. The 73 front end was revised to meet the 5mph requirement
but it sure is heavy. I will say one thing, the Bars beings attached to the upper
front bushings on 73's did make the front of the Car very riggid. This is a good
thing, but the 74 redesign (like it or not) is a much lighter design in addition
to being stronger.

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:32 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017