1971 k20 badmax
 

I bought a 71 c20 in 2014. Loved the truck but I was always wishing I had a 4x4. It was too nice of a truck to mess with so I sold it to my stepdad with plans to get it back later on and have money for my build.

I had previously had a thread on here but I failed to keep it updated so I am going to redo it here.

I bought a pretty rough 1971 K20 with plans to do a decent frame off with a nice, reliable power plant. Ideas flew around and I ended up with a Duramax. Here's the build my friends.

Re: 1971 k20 badmax
 

So then came the work. A bit rusty

Re: 1971 k20 badmax
 

I fixed my frame rust and slapped some paint on her. Rebuilt the axle and put her together. Then she went to the corner for a drive line removal.

Re: 1971 k20 badmax
 

Out she came along with stock springs. I traded for a 6" skyjacker. She then went to get her first round of bodywork, which I wasn't impressed with.

Re: 1971 k20 badmax
 

Then I bought my engine, trans, and transfer case along with the brains. I cleaned and slapped a fast paint job on the engine, then I sent my harness and computers off to make it all work. Harness was simplified by Ken Wolkens, and it looks pretty good. My ECM and TCM received tuning from Pela Motorsports. And some more bodywork.

Re: 1971 k20 badmax
 

Your truck has progressed a long ways! Congrats!

Re: 1971 k20 badmax
 

Some more body work and then we sat the engine and tranny in. Thank you sir!

Re: 1971 k20 badmax
 

Then she was headed off to a friends shop until it drives. I bought a HP Dana 60 that still needs to be installed. I also found a nice tailgate. I then decided I needed a beefier cross member. So I had a friend make this animal.

Re: 1971 k20 badmax
 

I snagged up my favorite, Welds! Wrapped in 37's. I also got a somewhat economical vehicle. Then bought a used t-case and had it rebuilt and slapped it in. Wiring has begun, and they put in my super beefy crossmember.

Re: 1971 k20 badmax
 

And this is where I am currently in the build. I went ahead and bought a 14 bolt 11.5" one ton rear so I had more meat out back and I got discs on all 4 corners.:metal: new intake as well! Intercooling piping is on its way along with my hog of a driveshaft. I think I'm going to man up and spend some money on A/C this weekend.

Re: 1971 k20 badmax
 

Very nice! You will not regret doing the AC now! :lol:

Re: 1971 k20 badmax
 

Oh I know! Now that I have a car that finally has AC, I am hooked!:lol:

Driveshaft is in the truck but I forgot to take a picture. 1480 u-joint at the case and a 1410 u-joint at the rear. Pretty beefy. The inter cooler plumbing is in as well. Steering column is about to be put in. Getting a new rag joint. Then once the AC gets wired I will have some piping for my turbskie. ;)

Re: 1971 k20 badmax
 

Skip the rag joint and go with a Jeep XJ shaft to eliminate the rag joint IMO.

Re: 1971 k20 badmax
 

Well, he's starting to get moving on it and I have no extra money.

Re: 1971 k20 badmax
 

you can get the xj shaft for $10-15. best mod ever

Re: 1971 k20 badmax
 

May I ask what it does?

Re: 1971 k20 badmax
 

Well I ordered my AC today through vintage air! Im pretty excited about it. Can someone buy my Dana 44 so I can get this 60 built ;)

Re: 1971 k20 badmax
 

the xj shaft gives you nice ujoints on both ends, for dirt cheap. eliminates the slack of the rubber disc.

Re: 1971 k20 badmax
 

Are they bolt in?

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Yep.

Re: 1971 k20 badmax
 

Well I have a friend with 3 totaled xj's so I'll go that route. Thank you for the help!

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If he wants to sell another let me know. I need one for my 76. I stole it off and gave it to a friend. Now it is steerless. :lol:

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If I can convince him to sell me any first.

Does anyone have a cheaper was to draw fuel from a 1/2" line other than a sump?

Re: 1971 k20 badmax
 

Intercooler piping mocked up with stainless. Blue tape is where she'll be welded, but both of his Tig machines are down for now. Until Lincoln can get him a new machine it'll probably be connected by boots and clamps.

Re: 1971 k20 badmax
 

I'd see if you can find some one to weld them first. How far from Pittsburgh Kansas are you? There's a board member that lives there that could probably weld these for you. What kind of tank are you using? A draw straw is a lot cheaper and can be obtained a lot of places. I use 1/2" ones in all my builds most times.

Re: 1971 k20 badmax
 

About an hour and a half. School starts the 21st of august and I will be in fort Scott (about 30 minutes north of Pitt.) If he doesn't get it welded soon enough I'll look into it! I think I'm going to cut the 3/8" line and then drill it to 1/2" and run some stainless 1/2" in its place.

Re: 1971 k20 badmax
 

I've been busy lately with moving down to college and such. I managed to sell my 3/4 ton axles, so now it's time to rebuild the Dana 60 front. Now I can have 4wd too. Intercooler pipes are welded but I failed to take a picture.

Re: 1971 k20 badmax
 

I've been busy lately with moving down to college and such. I managed to sell my 3/4 ton axles, so now it's time to rebuild the Dana 60 front. Now I can have 4wd too. Intercooler pipes are welded but I failed to take a picture.

Re: 1971 k20 badmax
 

Well my truck missed the goal of the carshow. But I took the C20, and still had a good time. 2,123 cars were registered in the show, there were some pretty cool cars and trucks there. Anyways, my axle rebuild is slowly coming along since I am only able to work on it on weekends. My Fass lift pump is mounted and he's doing some plumbing for the fuel. A/C is in the works too.

Re: 1971 k20 badmax
 

I'd say A/C is a must before you start driving it. Other wise you'll be driving it with no AC like me. :lol:

Re: 1971 k20 badmax
 

Haha. Yeah, I'd probably almost always drive the Camaro since it has pretty good A/C that I'm hooked on now.

Re: 1971 k20 badmax
 

The Dana 60 front has been blown apart and cleaned. We are now painting parts of it and it’s about ready to go back together. The AC has been hung in the dash and the holes have been cut!

Re: 1971 k20 badmax
 

Rollin on one tons:metal:

Re: 1971 k20 badmax
 

Very nice!

Re: 1971 k20 badmax
 

Nice to see a duramax k20 build here! Ive got a couple questions if you don't mind. First was the duramax rear axle wider than the d44 that was in the front? And how little lift could you run with a duramax oil pan? I have a duramax parts truck id love to use to power my 70 k20

Re: 1971 k20 badmax
 

I don't believe it was wider, looked pretty close to the same width. I never measured or anything. It all depends on how you do it. If you put the engine in your 70 frame, you will have to build your own motor mounts and possibly a crossmember. Also to keep it a 4x4 you will HAVE to use a 78-79 ford dana 44 or 60 (60 Recommended) to clear that offset oil pan. My crossmember as you can see is over kill. It can probably be done with 3-4 inches of lift, but there are a lot of factors that can change that. The pumpkin is large, so, how high you set the engine in the frame, how large of a crossmember is used will all determine. You will also probably have to trim the frame rails for the manifolds. The manifolds sit really low on a duramax. Or you could possibly body swap it? Hope that helps

Re: 1971 k20 badmax
 

Yeah it's always a cascade effect when you change anything major like that.I'm guessing you positioned it so the manifolds were an inch or so above the frame rails and moved it forward enough for the heads and turbo to clear the firewall?
Also no body lift right?

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Manifolds aren’t all the way above the rail, not possible without a body lift or maybe a cowl hood. There is some clearance in the firewall, but not a lot. No body lift, I hate body lifts.

Re: 1971 k20 badmax
 

Sorry my thread has been dead lately. Been super busy between work and school. The wiring is pretty much done, and we tried to start it. We have been running into some problems with it throwing codes, so once that is figured out maybe she'll start. First we threw a cam pos code, and now we are fighting a throttle pos sensor code, which seems correct as we have raw fuel dripping out of the exhaust. It is also possible that I have an injector leaking off.. I also threw an 8 inch lift on for clearance.

Re: 1971 k20 badmax
 

It's always something. Good luck with it and keep at it!