74 dart swinger weight reduction

[No rush]

G'day all.

I am sure this question gets asked a lot but haven't found the info I am after yet.

I have a 74 swinger that is mainly a strip car but want it to look like a street car still.

I want to start with the massive bumpers on it. I see there are fiberglass replacements but if I was to change to the fiberglass ones I would also like to make them smaller like an earlier model. Surely in 2021 there a companies that sell a conversion type kit to the small bumpers, especially the rear one (looks a lot easier). From what I have read you need a complete front clip to change the front, so maybe for that just get a fiberglass one and lighter brackets.

Does anyone know if say a 72 dart sports rear bumper would fit a 74 dart swinger with custom brackets ect?

Any info about the bumpers or weight reduction would be appreciated.

Cheers.

 

[krazykuda]

My friend used to tell me that I could loose 20 lbs of ugly fat if I chopped off my head...

So there's a start....

 

[Locomotion]

If your front bumper assembly has the "shock absorber" bumper brackets, like the rear, you can save a lot of weight by switching to '73 or early '74 bumpers, which have standard brackets holding them to the frame. But you will have to do some fabrication to attach the older brackets to the frame. The different bracket style attaches to the frame differently. Naturally, fiberglass would be much lighter.

The "shock absorber" bumper brackets bolt to VERY heavy reinforcements inside the bumper, like the photos show. The bumper bolt pattern is different between the style of bumper brackets used, but could possibly be welded to the regular brackets instead of using some of the carriage bolts.

Dart Sports started in 1973, but the rear bumpers are totally different. Earlier Swinger bumper assemblies, maybe even Valiant/Scamp, may fit, but with fabrication like the fronts to the frame. But the rear weight is where it will do the most good by helping with traction!

1976 only - Dodge Dart Lite - (Sport only) They are hard enough to find here in the U.S., so it would be unlikely to find one in Australia. But these cars had aluminum bracing on the underside of the hood, which saved about 12-15 lbs, which required lighter hood springs. Those inside bumper reinforcements were also made out of aluminum saving a LOT more weight.

 

[No rush]

If your front bumper assembly has the "shock absorber" bumper brackets, like the rear, you can save a lot of weight by switching to '73 or early '74 bumpers, which have standard brackets holding them to the frame. But you will have to do some fabrication to attach the older brackets to the frame. The different bracket style attaches to the frame differently. Naturally, fiberglass would be much lighter.

The "shock absorber" bumper brackets bolt to VERY heavy reinforcements inside the bumper, like the photos show. The bumper bolt pattern is different between the style of bumper brackets used, but could possibly be welded to the regular brackets instead of using some of the carriage bolts.

Dart Sports started in 1973, but the rear bumpers are totally different. Earlier Swinger bumper assemblies, maybe even Valiant/Scamp, may fit, but with fabrication like the fronts to the frame. But the rear weight is where it will do the most good by helping with traction!

View attachment 1715721217

View attachment 1715721222

1976 only - Dodge Dart Lite - (Sport only) They are hard enough to find here in the U.S., so it would be unlikely to find one in Australia. But these cars had aluminum bracing on the underside of the hood, which saved about 12-15 lbs, which required lighter hood springs. Those inside bumper reinforcements were also made out of aluminum saving a LOT more weight.

Thats some really good information. Thanks for writing all that.
My front bumper doesn't use the shock style mount only the rear, maybe replacing the rear mounts with some custom aluminium ones will do for now.
I thought that making the bumpers more attractive/ lighter would of been a popular modification.

 

[Locomotion]

Thank you.

The regular bumper brackets up front do have a steel plate sandwiched between the brackets & bumper, if I remember correctly. That can be removes for some weight savings without any custom work, You can also "swiss cheese" the front brackets. But please don't get carried away, especially with other parts of the car. You still have to maintain some degree of structural integrity. In fact, it's usually recommended to add frame connectors to Mopars because the bodies flex under hard use. Over time you get broken frame/body welds, cracks at body seams, and more issues. I made that mistake with my first race car. But also consider the safety factor on the street.

The rear "shock absorber" brackets aren't much heavier than the regular style. It's the inner reinforcement I posted a photo of that add a LOT of weight. But if you will be doing mainly bracket racing, the extra weight in back will help consistency, which helps predictability leading to more round wins. But it's your choice.

 

[No rush]

Thank you.

The regular bumper brackets up front do have a steel plate sandwiched between the brackets & bumper, if I remember correctly. That can be removes for some weight savings without any custom work, You can also "swiss cheese" the front brackets. But please don't get carried away, especially with other parts of the car. You still have to maintain some degree of structural integrity. In fact, it's usually recommended to add frame connectors to Mopars because the bodies flex under hard use. Over time you get broken frame/body welds, cracks at body seams, and more issues. I made that mistake with my first race car. But also consider the safety factor on the street.

View attachment 1715721425

The rear "shock absorber" brackets aren't much heavier than the regular style. It's the inner reinforcement I posted a photo of that add a LOT of weight. But if you will be doing mainly bracket racing, the extra weight in back will help consistency, which helps predictability leading to more round wins. But it's your choice.

Again thanks for the help and the info.

I already have sub frame connectors and a 8 point roll cage. As for traction it currently hooks up well but i am going to try out a 200 shot of nitrous next month. Already have traction bars, mono leaf, sliders, anti roll bar and good shocks. So I think reducing the rear weight shouldn't effect it to much.
Haven't checked out shipping on fiberglass panels yet but can imagine it won't be cheap.
Might go down the path of cutting out some of the reinforcements ect.
Cheers mate