1973/74 Plymouth Road Runner preservation with Q&A Feedback

[Bluesky10]

I am new to B-Bodies only, and just as new to a B-Body preservation. For background information, I am a mechanic by trade and have Chevy Muscle Car rebuild experience. However, when my wife asked me to consider my next project to be a 1974 Satellite like I had, and we dated in during high school, how could I say no

Long story short, I found a decent 74 Road Runner roller and planned to (please no stone throwing) clone my old car. However, our 16-year-old turned down a clean running 79 Z-28 I offered to buy him because he wanted the Road Runner. I explained the amount of work it takes to accomplish a project like this. He said he has seen me over the years do this and that he knows the amount of work, plus as he stated MOPAR or no car! So, starting October of last year (2022), my wife and I gifted him the car and the preservation was on. The reason I say preservation is because this is his first car, and I want to preserve it so he can enjoy it as soon as possible as most of us did and started our muscle car connection with. Now if this does not convince you he is dedicated MOPAR Muscle, he also turned down the keys to my wife's first car that I disassembled and rebuilt in early 2000. Here are then 1978 and now pics.

Now to get to the reason for this thread. He, to be referred to as the Kidd has been busy. Please keep in mind his preservation's purpose is to stop deterioration, get him in it, and he says one day he wants to restore in or send it to Kev-Dog at Kindig It. For now, he has been hard at it. Here is his progress. Keep in mind, he is doing all the work, and I only assist for advice and heavy lifting. Cleaning the Rat nest out First Fender Removed

Removing the K-Member

This leads to my question:

 

[Bluesky10]

Continued from Above: We have both BB and SB k-Members. The Kidd has a later built 318 that froze and cracked the block on both sides, so we picked up for parts. He was also recently given a clean late model 360 roller long block from a car guy friend, and I have a 440 short block he has disassembled and wants to keep for future use.

I have searched and cannot find a conversion kit to put a SB in a BB K-Member, or know of a way to accomplish this so one day in the distance future he can swap the SB out for the BB he would like to have one day. Any known methods?

In addition, has anyone retro-fit a late model 5.7 in one of the 73s or 74s? I am interested in info on this too.

Also, any leads on external body panels? I have bought 3 additional 74 Satellites for parts, and although several parts are okay for this project, the bodies are lacking as well.

Thank you for your help.

 

[#41]

As far as I know, nobody makes big to small block conversion motor mounts, however it's really not that hard to make your own. If you don't have a MIG welder, buy one. It will pay for itself many times over.

If I was in your shoes, I would build the big block and install it now.... even if there is a need to save up some dough first. Just build one engine and be done with it.

 

[Curiousyellow71]

I would do the 440. Good bolt in project for youngster.
440 source I think has adapter mounts available again. Occasionally shoemaker mounts come up for sale.

 

[Bluesky10]

As far as I know, nobody makes big to small block conversion motor mounts, however it's really not that hard to make your own. If you don't have a MIG welder, buy one. It will pay for itself many times over.

If I was in your shoes, I would build the big block and install it now.... even if there is a need to save up some dough first. Just build one engine and be done with it.

Thanks 41 and curiousyellow7, I would do that if it were not my son's first car. For now, just a semi-stock 360. I may mess around with my welder to see if I can come up with something. Maybe someone will see this and post a diagram that they have. I will also look up those venders listed.
Thank you for the help.

 

[YY1]

The conversion mounts above are for putting a BB in a SB K frame.

 

[YY1]

Didn't the OP say he had an SB K frame available?

Why not swap that in?

It's not difficult and you can replace the bushings and other front end parts while it's out since that probably needs done any way.

 

[Bluesky10]

Very cool, I figured I must be the only misfit to swap a BB for a SB, however guess which kits Schumacher are sold out of

 

[Bluesky10]

Thank you all for your time. Sorry for my back and forth. Wish we were sitting in my shop drinking tea and discussing. I have 3 SB Ks and 1 already refinished BB K from the RR and the 3 parts Satellites. If I let him have my BB K he can convert to a BB one day with little effort. I may not be alive when that time comes,but can always hope.

I never thought it would come to having to buy additional cars to accomplish this goal. However, it seems as if the reproduction parts companies have missed the mark with this one.

 

[YY1]

73 and 74 are really just now starting to get respected by the general Mopar population, and by extension, the aftermarket industry.

Unfortunately this also comes at a time of off-shoring issues and more recently high inflation rates, and business staffing and financial issues.

Schumacher has recently been sold, and is just now starting to move products again.

 

[Bluesky10]

Just spoke to someone at Schumacher, and it may be a couple of months before they do a production run on the BB K to a SB conversion kit. However, they do have a SB K to BB conversion I could put on the parts shelf for future use.

Products

426 Hemi, 440 Big Block, and 340 Small Block engine swap solutions for your classic Dodge, Chrysler, or Plymouth. Headers and bracket kits are designed specifically for your Charger, Dart, Cuda, Challenger, Valiant, and many others.

www.engine-swaps.com

Thank you all for your help. Stay tuned in for project updates and more questions.

 

[Bluesky10]

Good evening. A new question has arisen regarding our 1974 Road Runner rear leaf springs.

Can someone please provide me info on the operational difference between the Heavy Duty and Standard Duty rear leaf springs. We found one of the heavy-duty Leafs (Top to bottom number 7 leaf) broken.

Question One: is there any aftermarket replacement individual springs to repair this?
Second: What is the ride height difference between the Standard and Heavy-Duty Leafs?

I have 2 additional sets of standard Leafs, so I could use one of these, but I am wanting to assure of the ride height and performance difference, if any.

I did however give the Kidd my 8 3/4 posi rearend with Willwood disc brakes out of my 74 today.

Lastly, has anyone used the leaf spring rebuild kits on Classic Industries?

https://www.classicindustries.com/shop/1974/plymouth/roadrunner/parts/suspension/springs/

Again, Thank you for your help.

 

[MoparJimT]

Hey Bluesky10,
I have used the rebuilt kit and had a couple issues. I think it is for the standard springs, the u shape straps were too small to wrap the spring pack so had to source larger ones. I was also short on the thin metal squeak suppression separators because again I think the kit is for 1 less spring. Luckily a have a California car so most of mine were good it was just a preventative measure.

 

[Bluesky10]

MoparJimT, Thank you for the feedback. Good info to have, so with that we have disassembled a couple of sets we have and have reconditioned a set. The kidd has sanded, primed, and painted one set of 5 leaf springs, selected all the remaining serviceable parts, and all the bushings and additional parts are on the way from Rock Auto.

Thank you!

 

[Bluesky10]

The following post were copied from a previous thread I started to ask questions about engine conversions and leaf springs. I have moved this info here and hope it can help others in my situation. Thank you all for your help and advice.
From Wednesday April 5th, 2023

1974 and 1973 Road Runner/Satellite Engine Conversions, Rearends, Leaf Springs, and Other Info​

My son and I are new to B Bodies Only and keep finding more threads of intrest. I asked a question or two in the project thread, but now have discovered this tech thread. Although I received some great feedback and I wanted to provide what I have learned in case anyone else can use the info.
In case anyone is interested, here is the link to the project:

1973/74 Plymouth Road Runner preservation with Q&A Feedback​

I am new to B-Bodies only, and just as new to a B-Body preservation. For background information, I am a mechanic by trade and have Chevy Muscle Car rebuild experience. However, when my wife asked me to consider my next project to be a 1974 Satellite like I had, and we dated in during high...

www.forbbodiesonly.com

Previous Question: Are there any SB to BB or BB to SB K-member conversions out there?
Member Curiousyellow7 provided these options:

And Curiousyellow7 recommended Schumacher kits.

This is what I found out when I spoke to someone at Schumacher. It may be a couple of months before they do a production run on the BB K to a SB K conversion kit. However, they do have a SB K to BB K conversion in stock, and they offer the SB K to Gen. 3 Hemi conversion.

Now Leaf Springs bring up todays big question:
1. Can someone please provide me info on the operational difference between the Heavy Duty and Standard Duty rear leaf springs. We found one of the heavy-duty Leafs (Top to bottom number 7 leaf) broken.

Question 2: Is there any aftermarket replacement individual springs to repair this?
Question 3: What is the ride height difference between the Standard and Heavy-Duty Leafs?

I have 2 additional sets of standard Leafs, so we could use one of these sets, but I am wanting to assure of the ride height and performance difference, if any before I make a decision.

Lastly, has anyone used the leaf spring rebuild kits on Classic Industries?
https://www.classicindustries.com/shop/1974/plymouth/roadrunner/parts/suspension/springs/

I addition, I am looking to find books that provide all the nuggets of information on the 73/74 Road Runner/ Satellite. Also, the venders you have discovered for these great cars.

Again, Thank you for your help.

 

[Bluesky10]

Question 2: Is there any aftermarket replacement individual springs to repair this?
Question 3: What is the ride height difference between the Standard and Heavy-Duty Leafs?

Operation difference is the ability to more comfortably carry more in the rear of the car, or use a heavier trailer (tongue weight) if that's needed for you. Of course, if you went with a really heavy leaf, then rider comfort can begin to suffer.

Ride height should be very, very close to stock specs in an unladen vehicle. When buying leafs, you can now specify ride height over/under stock spec, or use differing front and rear hangers to accomplish your goals. I would suggest a call Espo Springs and Things for whole new leafs...., since if you have one broke, they are all indeed tired and weaker. You may find them quite affordable there. Good Luck.

 

[Bluesky10]

From: Lefty71

Thank you Lefty71. Greatly appreciated.

Leaf Spring Shackles, Bushings, Ubolts | ESPO Springs n Things​

Leaf spring shackles, ubolts, eye bolts, bushings and axle pads from ESPO Springs 'n Things. Both rubber and polyurethane bushings available.
www.springsnthings.com

I did consider Calvert Racing.

Split Mono Leafsprings/pair (421-36) – Calvert Racing, Inc.​

calvertracing.com
I have used them in the past, but since this is my son's first car and preservation, I was looking to save where I can and rebuild what I can.

 

[Bluesky10]

From: ZeroFiggz

Will be following this thread. I have had really good luck with firm feel . firmfeel.com Are you guys planning to run a rear swaybar?

 

[Bluesky10]

ZeroFiggz, Thank you for joining the thread. Before I realized I could have updated this thread name, I created another to have a larger (full car project) conversation.
Please join us there and I will move this info there also to maintain one thread.
New Thread Link:

1973/74 Plymouth Road Runner preservation with Q&A Feedback​

I am new to B-Bodies only, and just as new to a B-Body preservation. For background information, I am a mechanic by trade and have Chevy Muscle Car rebuild experience. However, when my wife asked me to consider my next project to be a 1974 Satellite like I had, and we dated in during high...

www.forbbodiesonly.com

Thank you, and look forward to seeing you there.

 

[Bluesky10]

Reply to ZeroFiggz above:

Will be following this thread. I have had really good luck with firm feel . firmfeel.com Are you guys planning to run a rear swaybar?

Concerning Swaybars, yes, the Road Runner had them installed and we plan to overhaul and re-install. Any advice on them will be helpful.