1973 C20 Cheyenne Super 454

[RPOZ11]

My simple thread project.
Been working this truck periodically over the years.
Threw a GM Nylon Timing Chain thus having to rebuild the 454.
I set aside the factory original 289 block and 7416 crank.
Picked up a used block and std/std cast crank and began the rebuild.
I reused the original 049 heads, leaving the stock valve sizing but added hard seats.
Retained the original low plane cast iron intake and slightly restored/rebuilt the Quadrajet.
Cam is a mild .475 lift with 112 centers.
Added the Thorley Tri-Y Headers.
Added an aftermarket aluminum water pump.
Harrison 4-row radiator rebuilt.
Turbo 400 is rebuilt now with a slight shift kit.
Complete rebuild of the drive shaft.
A few years back I had already installed the 3:21.1 gears and added a new Eaton Posi.
Will hopefully fire up this motor with in the day here.
Here is a pic of the 454 rebuilt and installed.
Exhaust is a simple build; nothing fancy.

[MTCK]

Cool rig. What are the plans?

[TrailerTrash]

looks very nice! love the orange engine

exhaust setup looks well done aswell

[RPOZ11]

MTCK..
After getting it running, get the 500 miles or so on the motor, get into the front suspension and rebuild it.
Then probably give some attention to the interior, then paint it.
I think its that crimson red; sort of an orange color. Has grey, black and red interior.

What went well, and I wasn't intending to use, that the Thorley Tri-Y headers actually fit quite well.
I have NO interference on any of the AC bracketry, but the passenger's side lower tube touches the factory gas hard lines.
So I had to massage the lines away some.
I am adding that HEI.
I'm tossing it around to add the GV, but I may not need it so much with the gears that are in it now

[Crcrft78]

Do you have any other pictures of the truck? Sounds like a nice project.

[RPOZ11]

I'll try.
Win10 is a new experience for me.
I'll see what I can post.

I got my brand new motor broke in this evening.
Had to swap out a defective fuel pump that fixed my problem at break in/start.
The 468 started right up.
Gave it a 30 minute break in period while adjusting the rpm ranges.
A couple of small things happened.
Had to adjust the choke setting for off cold idle start.
That brought my idle adjustment back to within reason.
Set the idle mixture screws.
2 of the trans cooler lines at the radiator tanks began to leak some.
Probably from heat and pressurizing the system.
Fixed that.
All in all, no leaks; per se.
These Thorley Tri-Y headers seem amazing.
No leaks.
No extra sound in the engine compartment.
Never expected such a good result with these.
Used some reusable header gaskets; new.
Proform locking header bolts; 3/8-16 X 1".
Work perfectly. NO leaks.
Will check these in a few weeks.
Runs @ 150*.
Oil pressure at 50Lbs.

[RPOZ11]

Originally Posted by RPOZ11

I'll try.
Win10 is a new experience for me.
I'll see what I can post.

I got my brand new motor broke in this evening.
Had to swap out a defective fuel pump that fixed my problem at break in/start.
The 468 started right up.
Gave it a 30 minute break in period while adjusting the rpm ranges.
A couple of small things happened.
Had to adjust the choke setting for off cold idle start.
That brought my idle adjustment back to within reason.
Set the idle mixture screws.
2 of the trans cooler lines at the radiator tanks began to leak some.
Probably from heat and pressurizing the system.
Fixed that.
All in all, no leaks; per se.
These Thorley Tri-Y headers seem amazing.
No leaks.
No extra sound in the engine compartment.
Never expected such a good result with these.
Used some reusable header gaskets; new.
Proform locking header bolts; 3/8-16 X 1".
Work perfectly. NO leaks.
Will check these in a few weeks.
Runs @ 150*.
Oil pressure at 50Lbs.

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[RPOZ11]

Originally Posted by RPOZ11

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[RPOZ11]

It's a bit dirty from sitting for the last 11 months while I've been redoing it.
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[RPOZ11]

Originally Posted by RPOZ11

It's a bit dirty from sitting for the last 11 months while I've been redoing it.
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Posted via Mobile Device

[RPOZ11]

Originally Posted by RPOZ11

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[RPOZ11]

Originally Posted by RPOZ11

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[Crcrft78]

Looks good, love the two-tone.

[MTCK]

Great looking rig.

[RPOZ11]

C/20 is running well.
Adjusted the cold idle choke.
Works now.
Tightened up the header bolts, intake, and thermo neck bolts.
Will adjust the rockers after 500 miles.
Has a slight off idle run but that should fix it.

I'm looking at my original seat material on the bench seat.
It's of a charcoal gray color with that pressed in texture.
Does anyone know if this material is available?
Who does seat material?

[MTCK]

These guys did an awesome job on making me an upholstery kit for my crew cab. They have lots of fabric options and are worth contacting. I installed the covers myself which wasn't too hard.

http://www.carandtruckupholstery.com/

[RPOZ11]

That's a VERY interesting website!
I'm surprised I've never heard of this one before.
Lots of vehicles covered.
Thanx for this !

[MTCK]

No problem. Customer service was top notch, they mixed and matched some fabrics for me, stuck to their timeline and the price wasn't too bad. Don't come across businesses like that too often...

[RPOZ11]

Hey all.
Been a few weeks since commenting on my rebuilt engine in the C/20 here.
I got her up to 500 miles on the break-in and was running well.
Still need to adjust those valves across both heads.

But I ran into another issue with this truck that my SWB was doing.
The mechanical fuel pump quit working.
Its an aftermarket new fuel pump thru the O'Reilly chain.
I had to replace the new one installed when I fired it, and now this 2'nd pump has failed.
On my SWB, I went thru 6 of these things.
Rather maddening.
Gas?
Manufacturer overlook on the diaphrams?
I don't know but on my SWB, I ended up installing a Holley Red Electric pump.

I am doing the same for this C/20.

What I am going to reach out for here is anyone's experience on fixing this issue.

My plan :
Holley Red pump
(now mounted on the outside of the frame just forward of the tank)
Holley Aluminum Fuel Filter, 100 Micron (before the pump)
Holley Fuel Regulator
2 metal Fram type inline filters, 1 before and after the regulator
Fuel pressure gauge
Holley 12-753 wiring harness and relay with inline fuse

Ive been digging around trying to educate myself on the vent lines.
I'm reading that most suggest making that work.
By keeping the fuel continuously moving from tank to carb back to tank.
(I need to see what Fuel Tank Vent exists)

I came up with the idea to install an inline fuel fitting after the regulator and before the hard fuel line going into the Quadrajet; closest to the QJ as I have available.
I'm going to try using a 1/8NPT X 1/4 vent fitting and reroute the fuel back to the tank thru the factory return line.
I have also read that I should consider that the ID of the return side back to the tank should be no bigger than .060.
Not to lose fuel pressure and to allow fuel movement. With my 1/4 vent side it will match the GM line size, I think.



What I am hoping for to work here is that this vent allows fuel to exit and continue fuel movement in order to prevent vapor lock and keeping the fuel cooler. I have not seen any info around addressing this in our trucks for these years.
What I don't know is how this will affect the rest of the factory tank system as installed.

This is what I am installing Sunday.

Anyone care to suggest anything into what I am attempting to accomplish here?

[Willowrun]

I think your tailgate ended up in my barn in MI.

[RPOZ11]

Originally Posted by Willowrun

I think your tailgate ended up in my barn in MI.

May I have it???😎
Mine I'm sure was taken off not long after the original owner purchased this truck.
I'm the 2'nd owner.
It was tough just locating the one I have on it here ,
And...
To have a mechanic drop a 9" Ford axle on the top of it.
These tailgates for these early years having the extra centering tabs on the bed-tailgate are hard to find
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[RPOZ11]

have re-post my image...

[RPOZ11]

Pics refuse to load properly after much tweaking...sorry

Well if you can understand what I installed via the clocked image above, I installed that 3/8 X 1/8NPT inline fuel fitting right before the QuadraJet fuel inlet; as close as I could while still retaining the fuel line feed for the fuel.
I ran the 1/4" gas rubber hose along the top of the 3/8 gas line back down to the factory metal vent return line used with the mechanical fuel pump.
Prior to installing the rubber hose onto the metal line, I ran about 2 feet of 1/4" hose as a lead to line up with the air nozzle from a compressor and tested the line to make sure it was clear and unobstructed.
This worked so well that it began the siphoning process out from the tank and gas never stopped coming out.
This was a good sign.
So, next weekend I will complete the install and fire this up and give it a test.
The gas tank vent is the last procedure that I need to do in order to know that all is venting properly

[RPOZ11]

OK
I got this thing running again.
The vent return line before the QuadraJet works.
So far.
Now, what I do need is a hot day to really put it thru the paces.
What this also helps with is keeping the fuel moving.
The constant fuel flow also keeps the Holley Red fuel pump motor cool.
Drove it about 15 miles; streets then freeway.
So far so good.
With the return line installed, fuel pressure stays just under 6 PSI.
I think also that it's understood that the return line should use a .060 size hole for th fuel return inside the hose.
I chose to run the .250 size.
What could work better with the .250 ID is maybe use the Holley Blue fuel pump.
More volume at high rpm's while retaining the .250 line.
I'll post if anything changes.
I'm just crossing my fingers that Vapor Lock and fuel pump issues are eliminated.
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[MTCK]

Nice work. Should be plenty warm for a test run. Enjoy the drive.