1970 Plymouth Duster 5.7 Hemi/T56

[B_Chandler]

Hi everyone. First time caller, long time listener. I've been working on this car as time and money permit. I got it from a friend as a roller. Factory B3 blue, Slant 6/auto/7-1/4. Bench seat, small bolt pattern drum brakes with A/C. The body work has been done...kinda. Previous owner was going to paint it HoK Candy Brandywine. Inner doors, jambs, trunk, and engine compartment are painted as such, the rest is HoK silver. I found the B3 blue when removing undercoat from the front inner fenders. I like that better than the candy color. The plan is to power it with an '09 5.7L Hemi backed by a T56 Magnum and an 8-3/4 rear. 4 wheel manual disc brakes. I'm keeping the torsion bar front suspension but using a QA1 K-member and front suspension goodies. I've put a good bit of work into it already so, enough talk, I'll get to the pics starting with the day I picked it up.

 

[B_Chandler]

We were renting a house when I got the car. It sat for about 2 years(?) In a tiny 2-car garage until we bought our current house. I was blessed to be able to build an actual shop. Contractors did the concrete and buildog construction. I've since run electricity and installed lights and fans, my trusty air compressor, and an outlet for my welder. In that same time period, I got busy on the car. I scored the motor from Marketplace. It was pulled because it had the hemi tick. I had intentions of freshening it up and the price was right so...

 

[B_Chandler]

I scraped and wire-wheeled factory undercoating and that's when I first saw the original color. I was trying to come up with a color that wasn't purple or lime green. Nothing wrong with those colors, they're just everywhere. Blue is too, but usually B5 or even Petty blue. I won't bore you with undercoating pictures. It was about this time I discovered FABO. Id hung around Mopar forums in the past. Scatpack, Moparnuts, and Moparts. When I started googling stuff, FABO was always at the top of the results. I did what I normally do, check out other people's builds, take what I like from each one and apply it to mine. I wanted to keep the torsion bars so while its nice stuff, Hemi Denny was out. It was hard to tell if Schumacher was in business or who was making their stuff so I went with QA1. Bought the K-member and the upper control arms. I was planning on disc brakes and needed big ball joints. I bought TTI mounts and a Mancini oil filter relocation kit. I'm a fan of Mancini racing, but in hindsight, it would have been better to source all that stuff on my own. I scored the correct Milodon pan/windage tray/pickup from Marketplace. With the k-member installed, and TTI headers purchased, mockups began.

 

[Kendog 170]

Nice. Keep the pics coming. Good luck with your build.

 

[B_Chandler]

Engine on the stand with the Milodon pan.

For some reason its only letting me attach one photo at a time now. So bear with me

 

[B_Chandler]

First time setting the motor in the car. The headers didn't stay on. Going in from the top, there's a dance that has to be done with the headers and the engine and both want to lead.

 

[B_Chandler]

I decided on power steering and thanks to the fine folks here I learned about the Borgeson box/ TTI header combo and went that route. I also ran across a killer

deal on a Holley Sniper intake. They seem to have a love/hate reputation, but I personally have yet to see anything beyond internet hearsay from either side. The stock 5.7 plastic manifold was a little melty around the ports so I didnt want to use it. The stock intake found a new home via marketplace and provided funding for future bad decisions.

 

[B_Chandler]

I kicked around transmission choices. I prefer manual transmissions and in the past have converted a few of my vehicles from auto to manual for that reason. I knew I wanted overdrive and was looking hard at the Tremec TKX. I looked at other builds and saw that there really wasnt that much more work to step up to a T56 and its one of those things where you only want to spend this money once. I bit the bullet, listed a kidney on Ebay j/k it was Craigslist, and bought a T56 Magnum, QuickTime bellhousing, Ram flywheel and clutch, and the T56 torsion bar crossmember developed by a member here and now sold through Modern Driveline.

 

[abodyjoe]

i like that intake.. looks like it will easily fit unde the hood too..

 

[DionR]

... T56 torsion bar crossmember developed by a member here and now sold through Modern Driveline.

You got a ToddRon crossmember from Modern Driveline? Was this recently or are we several years in the past at that point??

Last I looked they were discontinued, but I admit I am not following them closely. Ok, not following at all anymore since I am past that point now.

 

[B_Chandler]

You got a ToddRon crossmember from Modern Driveline? Was this recently or are we several years in the past at that point??

Last I looked they were discontinued, but I admit I am not following them closely. Ok, not following at all anymore since I am past that point now.

Last year, late spring/early summer. Had to wait for them to make a batch. It showed backordered online, so I called and they said they were making another run and would let me know. I cant remember if they let me know or if I looked online and saw them available again. Either way I snatched one up immediately.

 

[B_Chandler]

i like that intake.. looks like it will easily fit unde the hood too..

View attachment 1716469929

With room to spare.

 

[408 swinger]

What is the primary tube size on your headers? Have you fit everything on the K member and does that Borgeson play nice with the headers? Looking good!!

 

[B_Chandler]

1-3/4" on the primaries. Here's a link to TTI

https://ttiexhaust.com/TTi61WP.htm

Its tight. I had to massage a little at the driver's side torsion bar and may have to bump a tube a little at the steering box, but its in there.

Thank you!

 

[408 swinger]

Perfect pic. Thank ya, thank ya very much!!

 

[B_Chandler]

Okay, moving right along. Time to start cutting. The first time I mocked up the transmission, I did it without the engine. It made the in-n-out easier, but I discovered later when I tried it all together that more work needed to be done. My goal was to keep the cutting to a minimum to give me as much metal as possible to work with when it came time to fab a tunnel.

 

[B_Chandler]

Here's where I ended up cutting a little more out of the tunnel

 

[B_Chandler]

I picked up a Tanks Inc, EFI-ready fuel tank and a FI-Tech pump assembly. The sending unit is a generic Summit deal. They had to send me a second one because the first one came without hardware. They were super good about it. No complaints. I bought the copper/nickel fuel line and started bending it up a send and return pair to match the factory route. I was proud of myself(I'm not one of those tube bending artists) for making great bends that hugged the frame rail and followed the factory bends that moved the lines outside of the frame rail. The next day I'm under the car looking for a place to mount the filter and realized I did all that work to get the line outside of the rail only to be laying there figuring out how to get back inside the rail. Tore it all out and did a much simpler deal inside the rail, along the subframe connectors, found a nice place on the subframe connector to mount the filter and routed the line up into the engine compartment. For a filter, I went with an over-the-counter type filter instead of one of those fancy billet deals. Figured an O'Reilly Zone in Yourtown, USA would more likely have a 2022 Mustang filter than a Supercalifancyschmancy replacement element.

 

[B_Chandler]

More fuel line pics

 

[B_Chandler]

Astute followers and those who I haven't put to sleep with my rambling will notice the nice, shiny disc brake 8-3/4". That was a process. Started with a bare housing that came with the car. Another killer Marketplace deal scored me a 489 case with an open diff and a highway gear. This time I tapped Dr. Diff for everything. He was super helpful and made sure I got what I needed. New axles, a 4.10 ring and pinion, Powertrax differential, bearings, seals, and a disc brakes setup with the Explorer style parking brake. Word of caution, while IMO the Explorer parking brake is the better option, it's designed for Salisbury(?) style axles and fitting it to an 8-3/4 with the retaining plate at the flange is a challenge. My patience was tested and my profanity leveled up. Ended up having to disassemble the parking brake setup, mounting the backing plate and axle retainer and then wrapping the parking brake drums back around the flange. My sausage fingers were not designed for the task, but I managed and did so with less blood loss than Id anticipated.

 

[B_Chandler]

Finished and ready to hang. If only I'd ordered springs. With Debit card still warm and slightly smoldering from the Dr. Diff order, I called Espo Springs-n-Things and Mancini Racing. From Espo, I got the springs, shackles, bushings, and u-bolts. From Mancini came the shock mounting pins and plates. Fun fact, the slot mag in the pic is an old trailer spare and 14" in diameter and clears the rear brakes just fine. Not going to use it, but it makes a good roller for now.

 

[mopowers]

Great progress! I'm envious of your fuel lines. I tried doing 1/2" NiCop hardlines, gave up, and ended up going with pfte hose instead. Yours turned out great.

 

[340sFastback]

Super cool build. I chose the T56 close ratio for mine after years of analysis due to the gear ratios and outstanding reputation. I have had mine together for over a year now and am really glad I went T56 its super nice. You will love it

 

[B_Chandler]

Super cool build. I chose the T56 close ratio for mine after years of analysis due to the gear ratios and outstanding reputation. I have had mine together for over a year now and am really glad I went T56 its super nice. You will love it

I did alot of the same homework. The math worked out so that with a 28" tall tire, the T56, and 4.10 gears, it would hae all the fun of an A833 and 4.10s around town and have great highway manners. I cannot wait to drive this car! I got sidetracked lately with my truck, but now I've got my Duster focus back.

 

[340sFastback]

I did alot of the same homework. The math worked out so that with a 28" tall tire, the T56, and 4.10 gears, it would hae all the fun of an A833 and 4.10s around town and have great highway manners. I cannot wait to drive this car! I got sidetracked lately with my truck, but now I've got my Duster focus back.

Yep all the great gearing for hot rodding around and two over drives so no compromises anywhere.

I had 3.91s initially and with a 4 inch stroke small block it was a handful so switch to 3.73s when I swapped the Dana in. But I think 410s for your combo will work really well as long as you have enough tire on the rear.