New purchase - 79 C20 - questions

[HzSandman]

Just bought a 79 C20, 350 stroker (383), T400 Long bed. RHD as I'm in Australia. I have a few questions regarding these pickups...

Are the C20 and C10 frame heights the same - ie will a C10 bolt in notch fit the c20 frame ? (looking at LMC truck for parts) ?

Does anyone make a 3" dropped spindle for the C20 ? Still running 8lug and want to keep it this way. Has 2" spindles and 2" shackle kit. I want it lower.

When replacing the A arm bushes, can you use poly or do they only make the greaseable type still ?

[bharrison1]

nice truck!! i have 3" spindles on my 75 C20 i got em from AIM industries they are not popular on here but i have had their spindles on two of my trucks with no problems they bolt right up.

[78 Chevyrado]

Looks good!

If you have a 3/4 ton, you dont need rubber or poly bushings. They're solid steel. The only rubber in the whole front end is the sway bar bushings.



If they're not bad, I DO NOT recommend taking the A-Arm bushings off. They are a pain to reinstall and super easy to screw up. You have to screw both end bushings onto the shaft while simultaneously threading them correctly into the A-Arm itself. It was a huge pain for me.


If I remember right c10s and c20 frames have the same dimesions, except the c20 frame is a tad thicker.

[HzSandman]

I'll probably give the Aim spindles a miss, not many seem to like them here. I'm not sure what size spindles are on it, guessing 2" drop. Not sure if I should leave the current spindles in it and get some lowered coils. The A arms shouldnt be too much of an issue.

78chevyrado - thats super clean.... Just how it should be.

[manimal]

POL has drop spindles for a 3/4t. They advertise on here. The following pic will tell you everything you want to know about your frame. Good luck.

[bitchin85]

thats a nice truck! lets see some interior pics

[bb1979]

Good to see another fellow Aussie on here!!

I've got 2" drop spindles and shortened coils in the front of mine, shorter than stock shocks and the bump stop mounts removed/reshaped for clearance, running hilux front bump rubbers with 275/45/20 or 245/70/16 and am sitting at 100mm under the lower a-arms unloaded.

The rear is 2" lowered shackles, factory hangers remounted 2" higher than stock, shorter shocks and rearched springs with leafs removed, no flip or notch with early hilux bump rubbers mounted directly to chassis not to the plates riveted on the bottom of the rails. Have run 305/50/20, 275/45/20 and 305/70/16.

The rear could go lower but with the 275's on the rear I am approaching reverse rake (rear down nose up). If you want lower than that air bags are about the only choice or run the risk of being static dropped lower than 100mm with the police

Also I usually run without the front inner fenders for clearance however the police frown on it so I'm currently working on raising those to suit.

[HzSandman]

BB1979... Thanks for the info, that helps alot. I know about the 100mm clearance law, so want to keep above that...even if its only by 1mm

What/where are your springs and shocks from ? Do you have any pics of your rear suspension, ie the relocated hangers ? Any notch in your bed for the springs to clear ? I noticed with the 2" shackles the springs come really close to the bed floor.

I'm keen to remove some leaf's as the ride is harsh and bouncy. Would rather not do a notch as my 1990 c1500 had a notch and it was hard to get it to pass a RWC when it came time to sell it. How many leafs did you remove ?

The front currently has King springs in it which look fairly new, but definately needs to be lower....

My XF power steering box arrived last week, waiting on my pulley's, pump and some parts from lmc to get my steering sorted. Its a beast without P/S.

By the way did you have a silver c20 with a 454 in it recently for sale ?

[HzSandman]

A few more pics.
Towing a personal import - 1989 Ski Nautique 2001.

[96twodoor]

Originally Posted by HzSandman

A few more pics.
Towing a personal import - 1989 Ski Nautique 2001.

good looking truck man ,right hand drive still trips me out

[bake315]

Originally Posted by 96twodoor

good looking truck man ,right hand drive still trips me out

I know, right?

Wow, that engine compartment looks awesome all decked out in white!

[SS Delux]

Is that an all steel dash ? I dont see where the pad starts on the left side along the door frame.

[N2TRUX]

Welcome to the forum HzSandman. Nice truck there.

[bb1979]

I'll get some photos over the weekend, most of the stuff I have done isn't off the shelf parts, I have had my truck for 9 years now and alot of stuff I have worked out and fabricated using the stock gear as a template.

I am curious why you are using an XF box, I have a 88 up chev pickup box in mine (retains factory ratio and lock) the earlier transam units is also good substitute (faster ratio but with a loss of turning circle). These two units are the popular units used by conversion companies here.

It's been a while since I have been under an XF but I think the pitman arm points forward which means even if you could fit the pitman arm on backwards and have it steer in the right direction it would still need a large cage constructed to get it to bolt to the chassis rail.

Doing a power steering conversion and keeping all the geometry correct isn't the easiest thing to do, I can give you some pointers but it has been a good 8.5 years since I did mine back when I was 18 and I have killed way to many brain cells since then.

Basically it involves building a couple of jigs (easy to do this with the front clip removed). You need to know the relationship between the drag link and the frame and the stock pitman arm and the drag link. Once you have these jigs constructed remove the factory steering box and pitman arm and the shaft between the steering column and box, leaving the draglink in place. For my conversion I made a plate from 8mm thick (I think) steel which bolted to the 88 box and then sat the pitman arm/box into the drag link. Turn the box till the pitman arm lines up with the draglink adjust the angle of the box and mounting plate to match the factory one and g clamp it all to the chassis rail. I think I only had the lower and upper bolts holding the plate to the chassis rail as the middle one requires the chassis to be drilled and bolted from the inside of the rail. Weld the plate to the chassis rail.

Now the next step, the factory drag link is to short to line up with the drag link when the box is centered and the wheels are directly ahead (make sure your checking that off the idler & pitman arm location in the first place not the wheels as the tie rod may alter the drag link one way or the other). What I did was to cut the drag link before the bend and then cut a secondary drag link to make up the difference (I think you can get a drag link already fabbed up from Superformance in Queensland now) I drilled and inserted a strengthening bar inside these two pieces made yet another jig to hold it all together and and took it to a competition 4wd shop to have welded up and x-rayed. Unfortunally to the best of my knowledge there isn't another way around this without notching the chassis rail to move the box over. Also you will need to knock out the plastic pins it the connection shaft between the column and box and move the lower section back up towards the cab.

As you can see not the easiest of jobs hopefully there is enough info there that you can work it out. My conversion was based on one done on my dads truck over 20 years ago (its still going strong), I have done around 500,000kms of driving and alot of those being overly enthusiastic driving typically exhibited by young males.

Also if you intend on towing that boat I would suggest air bags over the springs or a notch because I would say that you will be riding hard on the bump stops if you end up as low as mine (I can get away with it because I don't carry or tow anything with it anymore, its ok when unloaded but bottoms out quick with small loads)

[HzSandman]

Thanks for the info mate, using a later box was what I was thinking would work when I first started investigating. I originally called superformance about a P/S conversion, they never got back to me so gave them the ass. I rang Eagle auto spares in Melb and they put me onto Trevor at Tranzco. He used to do a lot of conversions and said the XA-XF box was the easiest one to do. You dont have to modify the drag link, which as you have stated needs to be x-rayed and tested. He has a 1/2" plate lazer cut which you use to bolt the box to the rail, it uses the factory chev P/S pitman arm, which bolts to both the drag link and the splines match the xa-xf box. The xa-xf and c20 steering coupling are pulled apart and 1 unit is made from both - obviously ford end to the box and chev end to the column. A couple of pedestal's are turned up to mount the box to the 1/2" plate.
I should recieve my plate next week so I will be able to fit it all up in the coming weeks.
He has also adpated these to bronco's and said they have worked great.

I had bags under the rear of my 1990 too, I will see how it goes after I lower it. I'm definately keen to see some pics of what you have done to lower yours, especially moving the front hanger up the rail.

SSDelux, Dash is fibreglass. The only steel parts are the glovebox and ash tray...original items.

[bb1979]

Sorry couldn't get any pics over the weekend, threw my back out late last week and spent the weekend lounging around. Interested in seeing some pics of you steering conversion as you do it, might go out and raid one the wrecks out back of its unit and do a bit of comparison work. Meanwhile here are a few photos of mine stock in the rear dumped in the front and lowered all round. It has settled a bit more since these photos were taken (305/50/20 on the rear, 275/45/20 front)

What size tires are you running at the moment?

[Pop's C-10]

Do tha hanger mod..cut one full coil off tha front spring & call it done.

[HzSandman]

BB1979, Thanks for the pics. Crazy rake you had goning on there! Decided im going to pull 4 or 5 leaves out and get the pack reset. Front spring hanger has already been moved up the frame and the rear has the 2" shackle. Fronts will cop a cut coil as it has 2.5" spindles now. Will see how that goes.
Just waiting on some parts from LMC so I can rebuild the front-end at the same time. New LPG tank going in this week so I can get a RWC for it so I can transfer the rego.

Did you get lowered shocks at all ? The ride at the moment is pretty average, bouncy in the front, stiff out the back..

[walka]

Hows this thing coming along?

[HzSandman]

Finally got it roadworthy. Some boffin had damaged where the rear axle seal seats in the drum and it leaked oil all over the brake shoes. Looks like they removed it with a screwdriver. replaced seal and shoes on both sides. new intermediate hand brake cable, 2 new rear tyres. adjust hand brake. clear front parker lenses instead of amber.

Finally got every peice to my power steering jigsaw... so its going in this weekend. Also had custom U bolts made so I can pull 5 leaves out of the leaf pack to drop it a little more and hopefully soften the ride somewhat. Will try and get that done this weekend too.

Have some more parts from LMC coming so I can finish my front remodelling.

How about yours ?

[walka]

Mines comming along great, Im hooking up with the guy you mensioned in Hamilton this sunday at the Swap Meet at Ballarat, I was lucky to track him down. He has some Brackets that I need, He is also going to take care of the Drag Link for me. So all is good

[HzSandman]

Good stuff walka! Is the rat swapmeet on this weekend ? Been a few years since I've been, havent had an oldschooler than needed parts since I did the HK.