Plymouth B Body Mechanical Upgrade

Plymouth B Body Mechanical Upgrade

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HD Adam

Original Poster:

5,154 posts

185 months

Wednesday 15th July 2020
quotequote all
Inspired by Newsatten's hard work and pics of his Challenger during the resto, I was wondering if anyone would be interested in a thread on my 69 Roadrunner.

Fortunately for me, no bodywork required but quite a few upgrades happening.

I'm fitting full Hotchkiss TVS suspension & Willwood discs all round this time.

Once that's out of the way, 6 Pack EFI, Air Con and a change of the interior from the grey tweed (earlier resto) to something more original.

Cast your votes now to see greasy bits going on the Flying Banana biggrin






HD Adam

Original Poster:

5,154 posts

185 months

Thursday 16th July 2020
quotequote all
Allrighty then.

Bit of backround first.

The Plymouth was originally a Sport Satellite with a 318 2bbl & A904 auto.

At sometime in the past, it's been subject to a makeover and is now fitted with a 440 Six pack & 727 Torqueflite. Cool.

The bodywork & trim are great & the interior has been done in an 80's style grey tweed, which is very comfortable but I'm not a fan.

Mechanically, it's very good but it is just over 50 years old and 60's style suspension, even when brand new doesn't quite cut it these days.

Same for the brakes. The front had already been converted to 73 & up factory discs with single pot calipers which do work just like a 73 set of brakes rolleyes

There's no feeling like doing 75mph even at a safe distance and have a new car with big wide tyres, 4 or 6 pot calipers & ABS throw the anchors on in front of you as you close that gap.

So, upgrade time.

There's lots of kit available but I went for the Hotchkis TVS system rather than a mix & match approach.

Here's what you get.



Missing from the picture are front & rear sway bars.

Basically, you get heavy duty everything, geometry corrected A-Arms & springs, adjustable shocks. adjustable strut rods, heay duty torsion bars, quick ratio steering box arm & weld in subframe connectors to stiffen the chassis.

So far, so good & so expensive biggrin

Naturally, the first mission is to strip off all the old parts with all the fun that entails.
Hard to reach bolts, seized nuts, rusty bits etc.



Then, assemble in reverse order as they say.

But bugger. Look at that bunch of nana headers.
That's right where the new thicker torsion bars go.
Unfortunately, no option to hammer & dimple one of the pipes as that would virtually close it off so I had to spring for a new set.



Old headers. We have no clearance, Clarance.





New Headers. Much better.









Here's the new adjustable upper A Arms & shocks in position.





New rear leaf springs & shocks.



The subframe connectors bolt to the other side of the spring hangers





And a bracket is welded to a crossmember at the front for the other end.



Back to the Zorst. Well Crap. Doesn't meet up.



The car is currently on a trailer to an exhaust shop to get that sorted.

More to follow when the Willwood brakes go on.

HD Adam

Original Poster:

5,154 posts

185 months

Thursday 16th July 2020
quotequote all
newsatten said:
Great stuff son!

Cant wait for the update on how it actually all works on the road, nothing better than a proper user review!
Well it can't be worse than the standard set up silly

In all honesty, it wasn't "that bad" to drive around town in that floaty 60's 'Murican way.
Certainly comfy but wallows around like they all did back in the day.
Plus, quite easy to overpower it all with the 440.

I think we're all a bit spoiled by modern cars.
This is my daily driver here.



485hp, 6 pot Brembo's, Adaptive ride control etc. It's a new car.
When you drive this all week and then on a Saturday night take the old bus out it can be a bit OMG with the difference.
Obviously the Nana is never going to be anything like the Challenger but I'm hoping to make it feel a bit more up to date.

I don't have any way to quantify the changes when it's done but here's a review of the system on a 67 B Body, which seems to make quite a difference.

https://www.hotrod.com/articles/hrdp-0909-mopar-su...


Edited by HD Adam on Thursday 16th July 21:44

HD Adam

Original Poster:

5,154 posts

185 months

Thursday 16th July 2020
quotequote all
Turn7 said:
No gaiter on the rear shocks ?
Nope.

On that pic the suspension is at full droop but I don't think it will make a difference.

I don't take it out in the rain biggrin

HD Adam

Original Poster:

5,154 posts

185 months

Friday 17th July 2020
quotequote all
Matt Harper said:
Hey Adam

You could fill in the gap between your headers and the exhaust thusly...

Funny you should say that.

Here's a better shot of underneath before the header change.

The Y Pipes are for the electric cutouts.

Sounds great with them open but runs like crap.

I'll post a soundclip video when it's back together.

BTW, the Nana stays. I like the Nana biggrin



Newsatten said:
Yeah thats what i mean, You know how it drove before, so are there noticeable improvements in general handling, body roll, stiffness etc??
I just dont trust anything written by HOT ROD contributors, it all sounds so yank, and so false, hence why i was curious regarding your views! lol...........
It's not finished yet.

I'm borrowing a ramp at at a friend's shop so it has to be done between paying jobs.

There will certainly be a write up at the end.

HD Adam

Original Poster:

5,154 posts

185 months

Tuesday 4th August 2020
quotequote all
Some progress on the brakes.

Fronts are easy peasy, all just bolts up. Which is nice.





Rears? Not so much when going from drum to disc.

Had to pull the half shafts so whilst they're out, it's getting new wheel bearings & a bit of R&R.

Anyhoo, here's the rear set up on the bench with the calipers & new handbrake assembies.





I shouldn't be surprised but my 15" Rallye wheels don't fit over the new big discs & callipers banghead

You can get an aluminium 17" Rallye wheel which looks gorgeous, is v expensive but would mean you won't be able to see all the sexy new hardware.

I've decided to go with a classic set of polished Torque Thrusts in 17" with Nitto tyres so it's all on view through the spokes.

Here's the exact same combo on another 69.



Onwards & upwards.

HD Adam

Original Poster:

5,154 posts

185 months

Saturday 15th August 2020
quotequote all
A quick update for those still interested.

New Blingy 17" wheels have arrived.



Big Boy rear brakes on, new S/S brakelines and rear axle rebuilt with new bearings.









Basically, now I'm just waiting for the Hotchkiss front & rear sway bars, on backorder, which should be another 10 days or so and get the exhause hooked up.

HD Adam

Original Poster:

5,154 posts

185 months

Wednesday 19th August 2020
quotequote all
Power steering brake booster all hooked up.



New wheels on & alignment done.







Nice to be able to see the new brakes & suspension through the spokes biggrin



Still waiting for the Hotchkiss sway bars rolleyes

HD Adam

Original Poster:

5,154 posts

185 months

Thursday 27th August 2020
quotequote all
aeropilot said:
I can't believe you thought the new brakes would fit behind the OEM Rallye's laugh

[/thumb]
Acually, they very nearly did.

Only rubbed on the welds where the center piece is fitted in.

A small spacer would have taken care of it but decided that I wanted to see the bling.

Finally got the new headers connected to the old Zorst.

Looks & sounds great.



HD Adam

Original Poster:

5,154 posts

185 months

Thursday 27th August 2020
quotequote all
Turn7 said:
Is that switchable open headers I see ?
Yes, electric cutouts.

Sounds great with them open, runs like st.

Ok for burbling on tickover into a car show with my lumpy cam.

HD Adam

Original Poster:

5,154 posts

185 months

Wednesday 7th October 2020
quotequote all
At last.

The Hotchkis sway bars finally showed up (delayed due to a factory shutdown for the Rona) and have been fitted.

Beefy silly







So what's it like Mister?

Obviously, night & day difference.

How much of that is down to parts like bushings & shocks being replaced with new parts, I don't know.

I think I'd have to drive one with a stock rebuild but I've driven my share of 60's cars & it feels a lot more modern.
It corners pretty flat now and doesn't bounce up & down for 2 minutes when you stop at a light.

Of course, it's not exactly M3 levels of handling but it's a massive improvement and with the 4 pot Willwoods all round, it does stop like a modern car, allbeit without ABS.

Overall, I'm very happy with it and if you don't mind spending a few bob on a keeper, I think it's the way to go.

Oh, also won a Best Mopar trophy at a biggish show last weekend.

Niiiiiiice biggrin




HD Adam

Original Poster:

5,154 posts

185 months

Wednesday 7th October 2020
quotequote all
Thanks

Not much left of the show season now and all the major stuff finishes after Halloween.

Once that's all done, time for a few winter upgrades silly

Conversion to EFI

Vintage Air

Bit of interior work.

Also, the steering box has decided to start leaking as it needs to pump to the Hydroboost brakes now.

I'll be getting the Borgeson High Ratio box rather than rebuilding the 50 year old original.

So that puts the Roadrunner off the road for a bit over the winter which really isn't that wintery in Houston. There's still events to attend.

Sooooooo, I've bought this to run around in. tongue out

Got a 5.3 LS4 Chevy with 4 speed auto, rack & pinion etc.





Needs lowering, Olds Fiesta hubcaps & some fancy pinstripes & so but should be a nice little cruiser.