[FunctionalShaker]

The parts catalog calls for a different spring for the 400 hood. I've got several springs here and want to verify the dimensions of the 546325 (400) spring. Can someone measure theirs for me? Outside diameter, rod diameter, # of coils and unstretched length. Anything you can provide would be helpful.

[Ram4king]

I can't figure why there would be a different spring. A 400 hood and a standard hood weighs the same. I know there's a different spring when your car has ram air which adds a lot of weight to the hood. Maybe that's what they mean by a different spring listing.

[FunctionalShaker]

That makes sense, but the catalog only differentiates between the 250 - 350 (3848272) and the 400 hood. The springs I have, and believe to be from a 400 hood, have 26 coils and the diameter of the rod is a little smaller, plus the overall dia. is a little larger. I'll post a comparison pic when I have a chance.

[FunctionalShaker]

Here's a pic. The lower is the '272 spring, the middle is the one in question and the upper is that used from 71 and later.

[69Farburd]

I've lost track of how many sets of springs I have installed on my 69. I even tried Camaro springs, and have tied taking a link out of Firebird springs. None of them will hold the hood up. The springs for 71 and up look beefier. Maybe I should try those?

[tom s]

Maybe if converted to a RA hood?It does get heaver then.Tom

[FunctionalShaker]

No one with 400 hoods who can help out?

[69Farburd]

Mine have 29 coils, 1 7/16 outside diameter, 1/4 inch rod size, and measure 9 1/2 inches from end to end. But like I said before, none of my springs will hold the hood all the way up. My Ames catalog shows the same spring for all 1967-70 Firebirds.

[nashcar]

I thought I was the only one with that problem.

[FunctionalShaker]

That's the problem with aftermarket supplier's parts -- just because they fits, doesn't make them correct.

[69Farburd]

I just received a set of springs for the 71-81 Firebirds from Ames Performance. They are the same length as the 69 springs, but are about 1 11/16 diameter, have 25 coils, and are made of thicker material. I haven't installed them yet, but they feel a lot stiffer than the 69 springs. Hopefully they will hold the hood up and I won't bend the hood in half when I try to close it.

[MikeNoun]

Sorry, I missed this post! For the record, I've recommended the 70-81 hood springs for many years now.

I had the same problem for years, where the hood would droop a few inches after opening it wide, or gradually come down a few inches if the engine was idling and the hood was open. I tried new springs (Ames Perf, and Year One), didn't help. I then looked at the 70-81 Bird springs closely, and realized they were thicker. I tried a pair, and my problem has been solved now for over 10 years.

Only one person on the FGF site didn't have any luck with 70-81 springs, so he went a different route, using a second pair of springs (from a Volvo I believe) where he has a spring inside the factory spring, used as a helper, and that solved his problem. Not sure why he was the only one that didn't have success with the 70-81 springs on his 69, but perhaps he had a hinge issue or something. Anyway, the 70-81 springs seem to work perfectly.

And I agree about aftermarket products. The 67-69 Bird hoods didn't droop when new, which is proof that no one can make a proper 67-69 Firebird hood spring (obviously, they are using 67-69 Camaro springs and calling them Firebird springs, and Camaro hoods are lighter, hence the droop on a Firebird hood), but try and tell a reproduction parts company their product doesn't work, and you get the old, "Gee, never happened before, no one else has complained" excuse, to which most people simply toss the springs aside, and then look for alternatives.

Mike

[69Farburd]

Thanks Mike. I have been fighting this issue with the drooping hood (more than just a few inches) for many years. I have even tried cutting a loop off the springs. I now have renewed hope. I previously bought a set of porch swing springs from Ace Hardware (I think) to use as helpers. They wouldn't quite fit inside the 69 springs. If worse comes to worse, I think they will fit inside these new springs. Hopefully, I won't need them. These new springs seem awfully stiff. Do you have any tricks for installing them?

[MikeNoun]

For what it's worth, the springs I used were factory GM springs. Not sure if the current repro houses sell originals or repops of the 70-81 springs.

For installation, the easiest method is to prop rod the hood wide open (an old discarded wooden broom handle works good, you may have to trim a bit), then take an old fan belt, hook it around the front eyelet of the spring, and pull.

When installing, hook the spring to the rear eyelet on the hinge, then use the fan belt on the front eyelet of the spring, pull, and attach to the hinge.

Using this method, you can change both springs in about a minute.

[FunctionalShaker]

Another way I've used is to hang the hinge from something that can support over two hundred pounds, then using body weight a chain and S hooks to stretch it out and hook it on. This is for use when the hinge is out of the car. It takes about 200 lbs to stretch the spring far enough. It's actually simple to do, but takes two people to do it -- one to stretch, the other to hook. A wife works fine.

Note: The spring used on 70 birds is the same as one used for 69. The change to the larger spring came in 71.

Still haven't found the answer to my question regarding the difference in 69 springs.

[69Farburd]

FunctionalShaker, I don't want to hijack but others have expressed interest so I hope you don't mind. I installed the 71-81 springs (repops) and the hood still drops at least 12 inches. Does anyone have the GM part numbers? I think my next step will be to try the helper springs I purchased earlier. I hope I kept them.

[Region Warrior]

Pontiac only used one type of spring for all 67-70 FB's.
Found that more then likely the hinge is wore out if hood wont stay up.
But do have some NOS GM springs if interested.

[69Farburd]

Warrier,, When I had the car in the paint shop several years ago, one of the hinges broke. I bought new GM hinges, but the painter greased all of the hinge points. Do you think that was a mistake?

[FunctionalShaker]

The hinge points are supposed to be greased to prevent wear. I've found traces of factory grease cleaning them up.

3907626 is the number shown for '71+ springs.

[FunctionalShaker]

Found that the 69 assembly manual doesn't list a second pair of hinges/springs.