1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Aussie RHD 1975 C20 2WD Resto mod

Discussion in '2wd Pick-Ups C/R 20 2500 C/R 30 3500' started by pduffyd, Nov 11, 2019.

  1. Madhorn

    Madhorn Full Access Member

    Posts:
    485
    Likes Received:
    658
    Joined:
    Jan 16, 2017
    Location:
    AR-Arkansas
    First Name:
    Ken
    Truck Year:
    1977
    Truck Model:
    K10
    Engine Size:
    5.3/NV4500/NP205/4:56 gear/35in tires
    Great build
     
  2. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    Thanks Madhorn.

    Deep breath! Now to the power steering conversion.
    Ok, so the basic problem is the old 525 manual box has to go, but it puts the pitman arm against the chassis rail. Remember this is a right hand drive Aussie C20, its pretty easy to convert the LHD to Power steering, but I looked and looked, contacted companies over here about it, and they only offered light duty boxes. I wanted something a bit better like an 800 series box.
    SO all this being said, here is a before and after shot.
    20190331_135726.jpg 20200519_112527.jpg

    You can see where the pitman arm sits, its about 3" further out as the shaft is on the other side of the box.
    So I hunted down care of MOOGs web site for universal parts a drag link (Moog DS1426) that was about 3" longer, its off an 97-03 F250. I hate to have to put a Ford part on my truck but what can you do?

    20200517_141130.jpg

    after I got the drag link I checked the TRE (Tie Rod End) tapers, lucky for me were too small for the C20 TREs, I ordered up a 7Deg (1-1/2" per FT) reamer and opened out the Idler, Pitman arm, and L/H TRE. The R/H TRE needed to be bushed as it was a parallel hole, so I got a INSSTEER tapered steering knuckle insert from RuffStuff, opened out the hole and installed the bushing, it worked great.
     
    Last edited: Jun 7, 2020
    Dave M and FireTruck1984 like this.
  3. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    Ok, so now it was make an adapter plate to mount the new box to the frame.
    20200517_131853.jpg 20200517_1318.jpg

    So I measured the box and drilled this plate, then after all the fun, I found this online diagram, yes its a 4 hole box but the 3 hole uses the same measurements I understand. It would have been easier, to have this diagram first! Luckily for me the plate drilled out damn close, the 3/8" boiler plate was hard stuff. I mounted up the box to the plate and test fitted all the parts, then marked and drilled the frame. The bottom 2 mount holes went through the frame. I then added another 3 holes for 1/2" grade 8 bolts to mount the plate to the frame.
    Then it was take it all apart, to clean and paint. Oh yep, I tidied up the plate size too. The box to mount plate bolts were torqued up to spec, and locktighted for good measure. The 1/2" grade 8s were torqued F tight!! You can see the extra 3 bolts two at the top one underneath.

    20200519_112617.jpg 20200518_170358.jpg

    I had to sit the new box back a little to get the TREs in a straight line on the drag link, same goes for the Idler arm of course.
    I had to extend the L/H TRE as the adjuster was too short because of the different TRE mounting locations compared to the stock drag link. I used a ES2146S adjuster.

    20200519_112851.jpg

    So thats another job done.

    Next up change to valve springs on the rat!
     
  4. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    Ok, This is a job I have to do to allow for an RV cam to go in, Its cheap insurance as the engine is stock out of an 88 RV.
    The heads are peanut port 14092360. Now I know you are all going "get rid of those crappy heads!" To be honest I did consider doing just that, but Its going to be hauling and only crusin' so why do it?
    They are the perfect heads for low down stump pulling torque, which if im hauling a trailer is what I want, and I will be crusing the hwy at around 2100rpm with the 4L80 behind the rat. So a simple cam swap and new valve springs to match. The springs im using are comp cams 911-16.
    All sounds simple right, select the springs, change em out. Yeah, one word, rotators! Ok nothing too bad but not just on the exhaust, on the intake too! Not only that but the valve guide OD are different diameters!
    So the exhaust guide OD is about 0.616" but the intake are 0.626". No problem 2 sets of eliminators from Comp Cams 4779-8! Good for the exhaust at 0.623 ID but not the intakes, so out with the die grinder as the chromoly is damn hard stuff. A quick wiz around the inside with a die grinder did the job, I opened out 8 of them to about 0.632".

    20200523_120922.jpg

    That the stock measurements above
    Ok so the rotators are 0.300 think the eliminators are the same. When measuring the springs installed dont forget to premeasure the spring cup height, its about 0.140~0.144".

    20200523_124057.jpg

    Its hard to measure from the bottom of the spring pocket to the top of the spring when installed, so I just measured from the top of the spring pocket to the top of the spring and added that extra spring cup height to get the spring installed height.

    20200523_131928.jpg 20200523_132011.jpg 20200523_123721.jpg

    So here are before and after photos.

    The rotator, the replacement eliminator, and the installed height measurement.
    So the stock height of the later BBC head springs are 1.88"
    Here we can see I have 1.733' from the top of the rotator eliminator to the top of the spring.
    Earlier you could see the eliminator cup rebate is 0.144"
    So the over all installed height is now 1.733 + 0.144 = 1.877" I can live with will a 3 thou difference.
     
    Last edited: Jun 12, 2020
  5. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    Ok, as you can see I did this with out removing the heads.
    I took all the spark plugs out and rotated each cylinder in turn to TDC, and removed the rockers and push rods, I kept them in order for each cylinder as they are being refitted.
    I used a compressed air adapter to each cylinder in turn to hold up the valves while I compressed the springs to do this job of replacing the rotators and springs.

    20200523_124853.jpg

    A couple of tips to help, once the air is connected to the cylinder you are going to work on, lightly tap the spring keeper once or twice with a rubber mallet just to unseat the locks a bit.
    When you use the spring compressor the keepers and locks can easily be removed with a magnetic tool.
    When i removed the springs I also removed the umbrella oil seals, then replaced the rotator with the appropriate eliminator (resized intake or exhaust) installed new umbrella seals the springs and finally the keepers and locks, I used a bit of bearing grease on each lock just to help keep it located in the lock groove on the valve stem, prior to reinstallation.

    20200523_125957.jpg
     
    Last edited: Jun 12, 2020
    Dave M and Rusty Nail like this.
  6. Rusty Nail

    Rusty Nail Victim of Culture

    Posts:
    6,957
    Likes Received:
    5,147
    Joined:
    Jan 29, 2015
    Location:
    Your mom's house
    First Name:
    Rusty
    Truck Year:
    1977,1988
    Truck Model:
    C20, K5
    Engine Size:
    350, 350
    Seems like a lot of work.

    Thank for the wicked update and awesome pix!!
     
  7. MikeB

    MikeB Full Access Member

    Posts:
    1,564
    Likes Received:
    636
    Joined:
    Apr 4, 2014
    Location:
    Justin, TX
    First Name:
    Mike
    Truck Year:
    1969
    Truck Model:
    C10
    Engine Size:
    355
    My truck has gray POR15 on the bed floor under a bed mat. After 3 years or so, it's still shiny. I also used some on part of the inside tailgate panel that was exposed to the sun. It did turn flat gray and looked chalky, but I have repaired and painted the tailgate since then.

    I think it will be fine on your frame without any topcoat. BTW, you must add a topcoat before the POR15 cures, otherwise you will have to scuff it to get paint to stick.

    From their website. Applies to second coat of POR15 as well as color or clear coats:
    • Topcoat when first coat is dry but with slight finger-drag remaining, usually 4-5 hours.
    • TO TOPCOAT A FULLY CURED POR-15 SURFACE: Wet sand with 320 grit until gloss is dull, then paint.
    • POR-15® is sensitive to UV light (sun) and must be topcoated for prolonged exposure to sunlight. Failure to do this may result in long-term damage to the POR-15® coating. Topcoating is not required for areas not exposed to sunlight.
    Have to add that I once used POR15 (instead of resin) with fiberglass mat to repair some rust holes on a rocker panel. I then primed and painted the panel. It was supposed to be a temporary repair, until I could replace the panel. But 11 years later when I sold the car, the rocker panel still had no rust and no sign of the repair. Very nice stuff!
     
    Rusty Nail likes this.
  8. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    Hi Mike hi Rusty,
    Thanks for looking.
    Yeah that PRO15 is tough stuff, its still shiny as the frame is living in my garage, and dosent see too much sunlight!
     
    Rusty Nail likes this.
  9. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    OK, I just put the rocker covers back on the rat, as its gonna sit for a while. Oil down the bores and a sump full of oil, which gets pumped around the galleries once a month, and the engine turned over by hand. Its not the priority right now, but I dont want to neglect it too much either.
     
  10. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    So for the last few days I have been fitting up a Blazer fuel tank in the rear.
    I saw this Youtube video and went, yep great idea. So shout out to Dick's 4x4 Garage for this inspiration.



    So now I thought yeah Im gonna do this, out with the saddle tank, and in with a Blazer tank.
    A couple of things I looked for;
    1) I want EFI for the rat, so I need a baffled tank. (Spectra GM14C) its not baffled but has a sump.
    2) A bigger tank than the standard 20 Gal that was side mounted so the GM14C is 31 Gal. Tank straps to match are Spectra ST11.
    3) So I need a tank pump and sender unit for this, Spectra SP12L1H. It comes with a 12.5 ~ 25 PSI pump, so I bought a ACDelco EP381 to retrofit, as I will need about 58 PSI for the EFI im looking to run.

    That is the list of bits to fit, and this is what I need to fit.

    20200730_113604.jpg

    20200730_113639.jpg

    So here we go...

    First remove the brace between the rear spring hangars by drilling out the cold rivets.
    Keep it, as you can see its reused and moved rearward. The spare wheel hangar is also drilled off and re-purposed as the upper forward tank support.

    20200730_171735.jpg

    My C20 frame is a cab chassis style C20903, so the rear chassis top rail may not have the pre-drilled holes mine has.
    As you can see 6 inches back from the original position are another set of holes that would have fitted the brace perfectly, but the tank was just too close to the 14 bolt, and I would of had move the brake flex hose bracket too, no real problem, but I was just thinking I gotta get an exhaust in there yet. So another 2 3/4 inches back another two holes lined up on each side, one on top (inner frame top) and one slotted on the bottom (outer frame bottom). i drilled out the other two on each side after offering up the tank first to make sure there was enough room.

    20200730_171852.jpg

    The re-purposed spare wheel hangar, was flipped upside down and bolts just at the top of the rise in the frame rail on both sides.
    Have a look at the youtube video for a better look. The tape measure is a ball park measurement but it worked for me.
     
    Last edited: Oct 16, 2020
    FireTruck1984 likes this.
  11. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    Right, now I bought some 2"x 2"x 3/16" steel and a piece of 2"x 3/16" strap.
    I needed to make a front mount to both support the tank and stop it moving forward, and also I needed something for the tank straps to bolt up to.

    20200730_113740.jpg

    20200730_113726.jpg

    So this is what I came up with. With the tank in place with the anti squeak tape fitted, I installed the tank with the aid of a jack and measured an drilled the mount holes in the frame for the angle iron brace.
    In the middle underneath is an 8" piece centered and bolted up to support the front of the tank from moving forward, as the tank dosent really have enough to fix in place without it.

    20200730_115033.jpg

    Using the holes 6" back from the original rear cross brace holes I installed a strap (2"x 3/16") and bolted it up to support the top rear of the tank, it was an easier option than welding extra material to the rear brace as the hole are already there.

    20200730_115242.jpg
     
    Last edited: Jul 30, 2020
    FireTruck1984 and Rusty Nail like this.
  12. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    So with everything now in place I just had to drill the holes in the braces for the front and rear mount holes for the tank straps.

    20200730_134425.jpg

    20200730_133847.jpg


    Here is the finished install,

    20200730_115011.jpg

    Here are the fuel supply and return adapters ( GM to -6AN).

    20200731_131012.jpg
     
    Last edited: Jul 30, 2020
    FireTruck1984 and Rusty Nail like this.
  13. Rusty Nail

    Rusty Nail Victim of Culture

    Posts:
    6,957
    Likes Received:
    5,147
    Joined:
    Jan 29, 2015
    Location:
    Your mom's house
    First Name:
    Rusty
    Truck Year:
    1977,1988
    Truck Model:
    C20, K5
    Engine Size:
    350, 350
    Very nice!
     
  14. shanegtr

    shanegtr Full Access Member

    Posts:
    226
    Likes Received:
    163
    Joined:
    Sep 29, 2018
    Location:
    Perth, Australia
    First Name:
    Shane
    Truck Year:
    1989
    Truck Model:
    R2500 Suburban
    Engine Size:
    454
    Looking good so far
     
  15. pduffyd

    pduffyd Full Access Member

    Posts:
    94
    Likes Received:
    106
    Joined:
    Sep 27, 2019
    Location:
    Melbourne, Australia
    First Name:
    Paul
    Truck Year:
    1975
    Truck Model:
    C20
    Engine Size:
    454
    Been off the project for a while. Before anything physically gets in the way, like body work, I thought it would be a good idea to run some of the lines to/from the rear end.
    After installing the new tank I had a think about which side to run the fuel lines. As this is a Right Hand Drive truck, things are going to get crowded up front with the steering column and PS hoses etc on the RH side.
    So I partially installed the three Aeroflex aluminum 3/8" lines down the inside of the LH chassis rail, and installed -6AN fittings.
    I used 2" x 1" aluminum angle for the fitting mount brackets. All the AN fittings are Aviation grade from Aircraft Spruce, they are probably cheaper than race fittings, available in Anodized aluminum, steel, or stainless steel, 37Deg flare.
    The three lines are Supply, Return and Evap.

    Part numbers; -6D are aluminum -6 parts.
    Nut coupling. AN818-6D
    Sleeve coupling. AN819-6D
    Bulkhead flare union male to male. AN832-6D
    washer/gasket AN901-6A
    union nut AN924-6D

    The sleeve coupling aviation style, have a 37 degree chamfer to support the back of the flared line. Im not sure if race ones do, but as im in aviation I used what I know. The pictures I looked at like for Russel or Earl, dont show a good shot of the sleeve, from what I could find anyway. But check out the pricing you may be surprised.
    Im not sure if it was a good idea to go for the Aeroflex double anodized black line. When you use a line bender on it, it cracks the anodized coating, the tube is fine. As you can see I dont exactly have tight radius's on these lines. I should have gone the plain aluminum fuel line, but I wanted to have the chance of corrosion reduced, without using stainless lines.

    Here are a couple of photos.

    20200818_133129.jpg

    20200818_133021.jpg

    Then I laid in the brake lines from front to back.
    Hooked them all up and capped them off at the Prop Valve


    20200818_133215.jpg

    20200818_133222.jpg

    20200818_133254.jpg
     
    Vbb199 and Rusty Nail like this.

Share This Page