1974 Spring Hanger Question

[Bruzilla]

Ok, so I'm having a helluva time installing a set of MP SS springs onto my 74 Roadrunner. The rear wheels are sitting too far back in the well.

I think I've found out what one of the problems is, and that is that contrary to published reports the A measurement on 71-74 B bodies is not all the same. I keep hearing how 22" is that A length on all cars, but now I'm seeing references that state beginning with 74 cars, the A length is 21.25" vice 22".

Based on this, here's my plan, and if someone sees something that's gonna bite me in the butt please let me know. I have a set of 68-70 spring hangers that are about 6" long. From what I've read they're about an inch longer than than the hangers for the 71-74 cars (actually 71-73). So I am going to align the original OEM hangers with the 68-70 hangers, mark a location that's 1.25" from the center of the stock mounting hole, and drill a new hole as shown below.

The SS springs have a 20" A measurement, so that should bring me to the correct length.

Thoughts???

 

[idrivemopar]

I'm confused, did you get different length springs than what was original to the car? If you are talking about the distance from the front hanger, center pin to the spring box pin, I cant help, my 73's are 22.5 inches. By the way, 73 Roadrunner/Satellite is single year spring, wont fit other applications or years I have been told. Got mine from springs and things, and bolted on no problem. How do your new ones look compared to your old ones when you measure?

 

[Bruzilla]

What I think the problem is is that there are two different springs for 73/74. I've seen some that use a round eye on the front end and some that have an oblong eye. 73 was the first year of the rubber-isolated mounts, and I suspect they just modified the 72 and older springs they had on hand to make them work with the isolators and then switched to the whole new spring at some point during the production year. So some 73s have the round eye and are 22" and some of them have the oblong eye and are 21.25", and all the 74+ cars are 21.25".