What all components make up a F41 suspension package on a 1970 Buick GS?

Trying to find specifications on components that make up the F41 Buick suspension package on a 1970 Buick GS 455.
I know this was an option buy.

I bought a Buick GS 455 last year and have found some components that make up the F41 package. Not sure if I have all of them.

However, these components were not listed on the build sheet. So, I have to assume the previous owner had added these components. Unfortunately, he is very sick and not able to communicate with me.

The car has the rear sway bar. Has, what is referred to as a 4-speed braces attached to the differential and frame.

I know the F41 also had special shocks but don't know how to identify them.

Are there other components that I haven't listed or know about???

Where can I find specifications and photos of these components?

Regards, VET

 

The car would have had the boxed rear lower control arms, rear sway bay, frame stiffeners (what you are calling your 4-speed braces).

It would also have come with different rear springs, and different F&R shocks.

Depending on when your car was built the F41 shocks were either spirals or Pliacells.



If your car already has the frame stiffeners, boxed rear lower control arms, and rear sway bar, then it will look like an F41 suspension car as the rear springs all look the same.

The only outward appearing differences would be with the shocks.

For an early 70, the shocks would be spirals, just with a different part number.

For later 70 cars the F41’s came with pliacell shocks, while the regular suspension cars came with spirals.
Duane

 

Duane, thank you for calling me. Appreciate your knowledge and advice.

I want to clear up one major issue. This call was renovated in 2010, and sold to RK motors in 2015. The previous owner purchased this car in 2015 from RK motors.

From the receipts for left in the car when I purchased it in 2021. I found a receipt from Xtreme Restorations of Slatersville, RI.
for rear sway bar kit, dated May 4, 2016.

Labor: 23 hours, $$1,909.00
Rear sway bar kit: $300.00
Shipping & handling: $28.00
Paint, & supplies: $68.40
Supplies - sandpaper: $15.38
Total with tax = $2,320.78

To me, seems like 23 labor hours is a lot just to install a rear sway bar. Wonder if they added more than a sway bar.

Also (a month earlier) when I took a picture of the car frame, that's when I discovered the frame stiffeners.
Those didn't come with the car either. I was not expecting to find this on this car.

I have to assume; these are aftermarket add-ons.

My car will be out of the shop soon, I'm having pictures taken of the frame, shocks, springs and see if I have
boxed rear lower control arms. I believe all Buick GS's came with 4-link suspensions.

In fact, I've found other add-on's that were not advertised on this car, so this is somewhat a mystery car.

Thank you so much for your help, it really helps me trying to figure what the previous owner was trying to do to this car.
Regards, VET

 

All of the GS 455s in '70 I believe had the rear frame stiffeners (not sure on GS 350 or Skylark convertible). In '70 only the GS 455 (& all convertibles incl. Skylark) had the front X braces.

 

Front X braces, nice to know.
The previous owner, when into the engine and added aftermarket high compression pistons, look to be 11:1 models.

Caused major donation issues. This maybe the reason the previous owner stole this buick.
Found all kinds of repair recipes trying to fix this problem. Found he was using a lot of octane booster to help cure the problem. The 6 years he owned the car, he had only 3,000 miles on the rebuilt engine.
I was able to find a very good mechanic who was able to cure the dedonation issue (we hope).

I drove the car for the first time in 15 months being in the shop and it's running strong.
I'm feeling good that we finally got a handle on the engine issues.

We've found other mystery add-ons but won't get into that right now. Regards Vet

 

So just the rear springs were stiffer?

 

Yes,
I found that out when I started making my Chassis Sticker Sets.

You find all kinds of crazy stuff like this when you do your research and start making parts for people.

At least some of us do.
Duane

 

So they figured just the heavier duty shocks up front helped the front lean in corners.

All but the 70 GSX?

 

As stated in my first post both the front and rear shocks were different.

But only the rear springs were changed for the F41 cars. This was done for the “perceived” need for having heavy acceleration for these cars. (Go figure.)

As far as a GSX, do you think the Chassis gave a $hit if the car had stripes on it???

How much more do you think the car weighted????

They used the same suspension parts as any other 455 car with the F41 suspension.

As a matter of fact only 1 part bolted to the Chassis was different on a 70 GSX and that was the power steering box.

For 1970 they changed the ratio of the standard power steering box and did not offer a quick ratio box for any GS or Skylark.

…….but for the 70 GSX only, their power steering box was a quicker ratio then the 70 standard ratio. If you got a manual steering box they were the same.

I mean we all like the GSX’s and I have one, but this mistique that all kinds of pieces were special to them alone just makes me laugh.
Duane

 

I guess I have to stop reading claims of special rated springs in Buick brochures and articles on the GSX.
I'm also assuming it was just the G60 x 15 tires that said to make it handle the best.

 

Do you believe what Salesman say?

The Sales department were the ones that made up the Brochures so people would buy the cars. Maybe they just left out that the GSX’s used the same “special rated springs” and shocks as the other F41 suspension equipped cars.

You also cannot use articles as reference material. They are not Factory material and often have info included that is not factual.

If you ever had an article written about a car you would understand how difficult it is to get everything correct, and sometimes it’s impossible, as the article may have been sent in to meet a deadline before you are allowed to proof read it.

I deal with what the Assembly manuals show, and then verify the parts off the actual cars.
Duane

 

One other thing to note, you also need to be careful with using the Factory Dealership Brochures as Gospel.

There are certain year brochures that show options on cars that were never produced by the factory for that model year.

This is not the brochure’s fault as they were developed/produced way before the production runs started so they would be in the dealerships for the first day of the model year.

This often meant they were developed before all the car options were decided upon.
Duane

 

I find it funny or really sad actually that the advertising people who work for the manufacturer aren't car people.
Look at the one of the 70 GSX ads thats really a drawing of the car and specific parts. They list the Stage1 option as having the same 2.00 - 1.62 valves as the standard 455.

From a kid I always believed articles of car magazines, just thought these guys were pro's
Even Hemmings a few years back got the specs all wrong on the 70 GS buyers guide. I'm so tired of reading the actual horsepower of the Buick 455 is over 400 hp which still written today.

Edit: just saw your new post.. yes I use to take magazine articles as the Gospel

 

Also, rear upper control arms were different. GSX didn't get the front upper control arm bumper to allow for more squat.

 

Wouldn't the front rubber bumper help with body roll? Also if the car squats better on take off why would not having the rubber bumper help?

Are the different rear upper control arms different on the F41 or the GSX specific?

 

Matt,
Are you talking about the front rubber snubbers that mount into the frame?
Duane

 

Yes. Snubbers

As mentioned previously, there were no GSX specific chassis parts. Front upper control arm to frame snubber bumper has no bearing on handling in turns. they limit the amount of upward travel on launch. Without them the front end chassis can "hang" a little lower while the body goes up.

 

So what are the "Heavy Duty Wheels" that are mentioned? Just another sales thing? I never could find any part numbers specific to heavy duty wheels.

 

I don’t know, WG’s are pretty heavy, but were also available on other models.
Duane

 

https:www.youtube.com/watch?v=aPt-3rassLQ&ab_channel=CharJensRetroCars

Here we go Duane.. Exactly what you were mentioning At around 8:55 in he mentions the GSX has larger front and rear sway bars.