1973 K20 Build Thread

[TheWhiteElephant]

Hi guys, I'm new to this forum and thought it was time to start a build thread and hopefully share some knowledge. A few years ago I sold a 1979 K5 that I spent a lot of time building. I built it from the ground up, 3/4 ton axles, 7 inches of lift, CanBak soft top, custom bumpers, cage, 1973 front end, etc.



Marriage came, truck went , and now that I've sold my '65 Impala, I purchased the truck that I've wanted for a long time. I bought the truck on ebay from South Dakota, was planning on driving it down to South Texas, but found that shipping it would be cost effective.

My plans are to build a reliable, dependable, daily-driver work truck. I want to focus on the drivetrain for now and keep it really simple. One of the things I've learned if you spend too much time on your vehicles, something else has to give (namely, family time), so I'm going to keep this on a budget of time and money. It will be staying in the driveway, so I do not want a fancy paint job or anything that may attract thieves.

This was an old farm truck that spent most of its life on a farm hauling pigs. It is has a 350 GM target motor/350th/NP 205, dana 44/14 bolt drivetrain. I'm going to focus on keeping it original for the time being and just clean things up and freshen up whatever I can. I have never seen an engine this dirty. The farm dirt mixed really well with the leaky gaskets to create a very tough, baked-on clay coating. This junk was EVERYWHERE.

After going through it with a borrowed 2500+ psi pressure washer, I still had a lot of scraping to do. I was originally going to re-wire the entire truck, but found that the harnesses were in decent shape, so I will only clean them up and repair the necessary areas. I am going to replace all parts that require maintenance and take it from there. Here are a few pics to get started beginning with my old Blazer...

[1985-GMC]

That was a nice blazer you had! Looking forward to your build!

[TheWhiteElephant]

Thanks, I'll be posting pics of the "new" one in a while...

[TheWhiteElephant]

By the way, I still have dreams about that K5 and I sold it years ago. Here are photos of the day I received it from the transport company. Great guys, delivered earlier than promised. These pics kinda bring a tear to my eye...

[TheWhiteElephant]

Here are photos of the engine prior to the clean up...

[TheWhiteElephant]

Another one...

[TheWhiteElephant]

Here is the engine during clean up. A few cans of Oreilly brand degreaser, wire brushes, carb and choke cleaner, and good ol' elbow grease. Take note of the cracked exhaust manifold. Both were cracked, actually. I decoded them and found they were likely from a 1971 Corvette. I also decoded the Quadrajet and it was also likely from a '71 Vette or fullsize Chevy.

[1985-GMC]

I like it! Have you ever tried oven cleaner for cleaning a engine like that, and what year is it?

[TheWhiteElephant]

Here is the engine after removal of all accessories, additional pressure washer time (4 days total with the pressure washer), and I also bought a gallon of DEP industrial strength degreaser from Home Depot. I highly recommend that for the toughest jobs. Works instantly. I used a drill and circular wire brushes, too. I still wasn't finished at this point.

[TheWhiteElephant]

Originally Posted by 1985-GMC

I like it! Have you ever tried oven cleaner for cleaning a engine like that, and what year is it?

I've never tried oven cleaner, but the DEP degreaser that I used removed that gunk pretty well. I really should try oven cleaner, though, because the DEP stuff stinks and kills the grass.

I'm not sure on the year of the engine, I got the code on it but haven't spent much time decoding it. The truck is a 1973 model. I forgot to mention that it also has a wood bed. I'm not too sure, but that seems somewhat rare for a '73(?)

[TheWhiteElephant]

I wanted to keep the manifolds on the truck (I'm tired of headers at this point in my life), and specifically wanted to keep the ram's horns. I searched high and low and finally found a good set on ebay. $150 shipped. Quality seems decent. I also ordered a set of stainless steel bolts for the manifolds. Here is a comparison...

[TheWhiteElephant]

I live in a neighborhood with a homeowner's association and am doing all this in my driveway, so I don't want to upset the neighbors with my junk in the driveway (my wife is embarrassed enough as it is). In keeping with my simple do it as you drive it theme, I therefore decided to give the engine the good old spray can rebuild as opposed to yanking the engine and making this a longer term project...

[TheWhiteElephant]

I didn't want to get too fancy with the engine as I plan on really driving this thing, but I do want durability. I purchased a Milodon oil pan and timing chain cover along with my all-time favorite Edelbrock valve covers. I also purchased a new set of ARP black oxide bolts to replace the old hardware. In the last photo I am just test-fitting the valve covers. I installed a one-piece Milodon oil pan gasket. First time I've used one of these and at over $30, it better work. That's also a new (non-reman) Oreilly water pump (which I later painted cast-iron gray for contrast).

[1985-GMC]

I love those valve covers!

[big_b]

i like the ram horns. the big problem with those is the left side is angled back and they always break at the bend. finding originals that arent broken is pretty hard.
your truck looks well optioned and motor is gonna look awesome!

[TheWhiteElephant]

Next I started to clean up the wiring. As I mentioned earlier, I wanted to initially replace the entire wiring harness, but figured I didn't really have to and saw the money would be spent better elsewhere. I removed all the old wire loom and tape and individually cleaned all the wires with a rag, spray bottle, degreaser, and soapy water. I put in new fusible links at the starter wires (amazing how many parts store guys have no idea what fusible links are), and arranged the wires with small tie wraps, new plastic wire loom, and I routed them on the firewall with Adel clamps. I scrubbed the firewall with light scouring dish sponges (thanks, honey) and soapy water. I will go back and really clean up the engine compartment with these later. I also installed a new detent/TV cable--found the old one was not working and removed the transmission oil dipstick. It was leaking really badly at the o-ring while the truck was just sitting there parked.

[TheWhiteElephant]

Originally Posted by big_b

i like the ram horns. the big problem with those is the left side is angled back and they always break at the bend. finding originals that arent broken is pretty hard.
your truck looks well optioned and motor is gonna look awesome!

Thanks for the kind words. Yeah, after test-fitting the rams horns I found it would be much easier to set up the exhaust with the log-style manifolds, so I better find me a good exhaust shop. I had a really tough time removing the starter because the exhaust pipe was very close to the starter, leaf spring, and transmission lines. I'm going to see how it all works out. I'm seeing the best route for the exhaust on the right side is above the starter.

[TheWhiteElephant]

The transmission lines were a mangled mess so I bought a new set from Classic Industries. They fit really well and I opted to go with the original material as opposed to the stainless steel ones due to the price difference. I pretty much work on this thing as time allows and in short spurts, and now with daylight savings I'm going to have to use the shop lights more.

Here I have reinstalled the balancer, water pump, routed the wire harness down to the starter, installed the valve covers, and the new fuel pump (not visible).

I also rattle canned the frame with black semi-gloss Rustoleum. I prefer semi gloss over gloss because the semi gloss hides imperfections in the surface while gloss brings them out. Only problem with Rustoleum is that it takes a long time to dry.

I wrapped the transmission lines with 3/8" fuel line and tie wraps where the 2 lines touch. I also changed the transmission oil filter and gasket.

[TheWhiteElephant]

Right now I'm in the process of rebuilding the Quadrajet. Hopefully I'll have time this weekend to finish it up. I also hope to install the new (reman) alternator, starter, and power steering pump and lines. I will then remove the fuel tank and send it along with the radiator to the radiator shop for a complete flush and radiator refurb.

I also replaced the cap, rotor, points, coil, and will put in new wires and plugs. I really should have bought an HEI from Summit with the money I spent on the tune up of the distributor, but that will have to come later now.

[dccarpenter]

Great photography and thread, please keep up with it. I'm trying to do a similar on-the semi cheap build of my '75 K5 Blazer and this is helping out with some ideas.

I'm assuming your doing so much replacement of parts for reliability reasons? Have you compression tested the engine to assess it's internal health? Anything you did to test the transmission?

[TheWhiteElephant]

Originally Posted by dccarpenter

Great photography and thread, please keep up with it. I'm trying to do a similar on-the semi cheap build of my '75 K5 Blazer and this is helping out with some ideas.

I'm assuming your doing so much replacement of parts for reliability reasons? Have you compression tested the engine to assess it's internal health? Anything you did to test the transmission?

Thanks for the kind words. Great questions, too. To be honest, I only drove it a few times after I bought it. I was surprised that it idled really, really smoothly and wouldn't smoke. It would start right up with no issues. It definitely needed a complete tune-up. In retrospect (and this is something I have thought about many times since I started), I probably should have just done a complete tune up, ran it for a good few weeks to see if any issues came up, and then started with the refurbishing.

On the plus side, the rockers, crank/rods, and oil looked in very nice shape with absolutely no sludge when I removed the covers and oil pan, so I was happy. The transmission was rebuilt a few years ago and driven very little after that. I did remove the transmission pan and replaced the filter and noticed that the oil was nice and red, didn't seem burned at all.

You are correct, I am replacing the starter, alternator, belts, and hoses all for reliability reasons. I do this on all the "new" cars I buy just so that I may have peace of mind and a date of replacement for my personal records.

I'm going to look at a possible parts '73 this weekend.

[TheWhiteElephant]

I decided to order a new transmission dipstick. The original one was cracked and the tube o-ring was shot. I initially purchased a Hughes unit but it didn't fit right. Then I bought a Lokar 36" one and it was way too long.

I finally bought a Lokar Anchor-Tight dipstick and tube in the black anodized model. This should (better) be the fanciest thing under the hood. It is quite pricey, but at least I'll never have to worry about leaks. It screws onto the transmission dipstick hole (must remove the pan---good thing I hadn't yet put the fluid in) and it creates a positive seal. The dipstick has a quick release with bearings. You have to slide the silver part down to release it. You also don't need the "special" funnel adapter to fill the trans as the tube is large enough for a standard transmission funnel. It also has a quick release down where it mounts to the transmission. It's a lot more than I wanted to spend on a transmission dipstick, but oh well...

The dipstick doesn't look long enough in the photos because I am bending the tube, causing the dipstick to move into the tube.

[TheWhiteElephant]

I also saw a pretty nice driver '73 grille on ebay that I got this week in the mail. I was pretty impressed in the condition...

[Matt Man]

looks good bud.

[TheWhiteElephant]

Originally Posted by Matt Man

looks good bud.

Thanks, Matt.