73 vs 74 Leaf Springs

[Bruzilla]

I've been looking for leaf springs for my 74 Road Runner and there a whole lot more springs for 73s on the market than for 74s. So I was wondering what one needs to do to install a set of 73 springs on a 74 car, or if such an engineering feat is even possible?

 

[WP29440SE]

73 through 79 B bodies are the same platform. they all interchange. I have used 77 springs on a 74 , 73 on 74 and vice versa. right now I have an entire 77 charger suspension on my 74. the 73 and 74 are virtually identical.

 

[Nacho-RT74]

there is ONLY ONE diff between 73 and 74s springs and not in ALL B Bodies, and is the oval front spring eye. I meant not in every B body because I have known my car is not the only 74 with still round front spring eye, where the only difference with 73s is the thicker bushing isolation on 74s using also a smaller bolt on a same bracket with smaller hole for the bolt.

so if your 74 got a round spring eye, is a straight interchange with maybe just the bushing difference... WHERE if you don't want to deal with that, can simply enlarge the hole on your bracket and use the thicker bolt like earliers

Now... if an original oval setup can be replaced with a round setup in a straight change... dunno. Would need to check the bracket difference for a diff location for the bolt... and if they are really diff, would need to replace also the bracket

- - - Updated - - -

http://www.forbbodiesonly.com/moparforum/showthread.php?64795-73-74-RR-difference

pics there.

the pic where the oval setup is shown seems to have same bracket than mine, but never to known if not compared side by side ( or getting measurements )

 

[Bruzilla]

I knew about the oval vs round, but was wondering about lengths, and they seem to be the same.

 

[idrivemopar]

When I got my 73 RR springs from ESPO Springs and things, they said the 73 RR spring was a single year spring, you might give them a call and ask, they may be able to answer your questions.

 

[WP29440SE]

I knew about the oval vs round, but was wondering about lengths, and they seem to be the same.

if you have springs with the elongated hole, measure from the back of the perch to the spring eye, and I will go outside and measure mine, I have the round spring eyed springs off my 74 outside. I am pretty sure that the springs are the same length. I cant see there being a "special" spring length for one year only.

 

[Nacho-RT74]

stablishing 74s got springs with elongated front spring eye on the books ( althought we already known is not totally thruth ), yes, 73 would be only one year production againts earliers just for ONE reason...

the guide stud for the axle, carries bushings on bottom and top to fit into the isolation pad, not present on 71/72s. Guide stud is also thicker ( 3/8" against 5/16" of earliers ) making larger holes on leafs for the stud. They are also longer to fit the bushings I'm talking about.

then IF we think on a vendor selling round front spring eyes springs WITH front bushing mounted, and also since it seems 74s with round spring eyes got thicker isolation ( is on that way at least on mine ) making the center bushing smaller, this make also a one year production for 73 and one year production for 74s. Exception for this is if springs are sold without front bushing, where 73s and 74s would be the same.

I bought 71/72 springs locally and had to modify the guide stud setup myself ( drill and replace the stud ) beside install correct bushings for the exposed reasons, thats why I know this.

 

[WP29440SE]

just for the sake of comparison, because this has peaked my interest, my 48,000 original mile 74 charger SE has the original springs, and they have the round spring eyes. from the back of the perch to the center of the bolt is exactly 2 1/8" . I would like to know what the measurement of the elongated spring eye perch is , if anyone knows.

 

[runnin74]

just for the sake of comparison, because this has peaked my interest, my 48,000 original mile 74 charger SE has the original springs, and they have the round spring eyes. from the back of the perch to the center of the bolt is exactly 2 1/8" . I would like to know what the measurement of the elongated spring eye perch is , if anyone knows.

I posted the previous image of the oval spring eye from my 74 Road Runner. From the mounting surface for the front perch to the center of the spring eye bolt measures 2 3/4 inches. See attached pic.