1973 4wd to 2wd K5 Blazer Build
 

I have always wanted to build a Square Body Blazer. I have built a number of trucks, but never built one I could not part with. This will be my journey in the world of Square Bodies. I am old school and tend to believe I can do it all myself. My last build was a bagged 59 Apache. I have found the best way to start is just jump in head first and figure it out. So here goes...

Re: 1973 4wd to 2wd K5 Blazer Build
 

For this build I found a 1973 K5 4wd to start. It is in pretty good shape considering it was sitting in a field outside of Houston. I made a deal ($1200) and dragged it home. It has a 350/350 and is lifted 6 inches. First I had to figure out how to convert it to 2wd. I have seen others swap components and fight a good fight, but my option was to to find a 2wd donor and swap parts till I get it how I need it.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Hell yeah

Re: 1973 4wd to 2wd K5 Blazer Build
 

Next, I had to find a donor with what I needed. I searched and found a 75 locally and dragged it home.

The good: It had a top, and decent interior, a lot of parts I needed and it was 2 wheel drive.

The bad: The body was mostly junk.

Re: 1973 4wd to 2wd K5 Blazer Build
 

First things first, teardown.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Over a weekend, I got the body lifted up and dragged the frame out and off the trailer. I have limited room so that is the only way I could do it.
It was a real pain in the :( but I got it done. It is not the easiest or safest way but I took my time and worked as safe as I could.

Re: 1973 4wd to 2wd K5 Blazer Build
 

The next day I went online and ordered everything to fix the front.
2.5 Spindles and 2" drop springs
Upper and lower ball joints
Upper and Lower Urethane Control Arm Bushings
Rotors, Calipers, Bearings, Seals, Brake lines, Inner and Outer Tie Rods

I cut the humps off the LCA's, pressed the new bushings in and put it all back on.

I found a set of 7" and 8" rally's for 75 bucks locally, cleaned them up, painted them and put some tires on them.

Re: 1973 4wd to 2wd K5 Blazer Build
 

I sorted all the 2wd parts and labeled them for reference. I set the top on the 4wd and dragged the 2wd frame home.

On the 2wd body, I saved the rear floor in one piece. It is in fantastic shape and I plan to swap it also.
The factory low back buckets and rear bench can be recovered, and will be nice.
I saved the low rise tranny hump, the roll bar ( might use ), steering column, wiring and all the A/C stuff.
All that is left is the rough doors and the windshield frame which I am going to trade or sell for stuff I need.

I also found a 81 glass top about an hour north of me with nice sliding side glasses for 50 bucks. I removed the glass and
traded the shell to a guy for a 2wd transmission cross member for the frame

Re: 1973 4wd to 2wd K5 Blazer Build
 

Today is back brakes day. New everything except parking brake cables. Been awhile since the brakes had been serviced last.

I also put the new idler arm on. That can in front of the frame is a molasses soak for rusty parts. It works great at 1 part Molasses to 5 parts water.

I am putting big tires (30x9.5x15 and 31x10.50x15) on since they are the ones I used on my 59 and I could swap them with the 22's that were on it sometimes.

Re: 1973 4wd to 2wd K5 Blazer Build
 

I'm curious which way are you going with this. Will it be a 73 4x4 on a 2wd frame? Or a 73 body used to save a 75 2wd?

Re: 1973 4wd to 2wd K5 Blazer Build
 

I have a title to the 73 so I will go that way. It will be a 73 4wd with modifications. I may keep the motor to put back in it.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Got the rear brakes buttoned up. Sanding and smoothing the frame for paint. Not the kind of build that requires powder-coating. Ordered some brackets to flip the rear axle. I am going to cut off the old perches and weld some on the bottom because I think it looks better. Figured out I have a 2.73 gear in the rear-end which would allow me to run a TH/400. ( I have a good one in my storage) Since it is gonna be a cruiser the 700r4 overdrive might be useless.
Boring stuff that does not warrant pics.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Going to try something different. I am swapping the rear leaf springs on the Blazer. I have a pair of leafs that came off an extended cab S-10. They are within 1/4" eye to eye but are so much nicer. I hope they will smooth out the ride also. They have anti squeak pads and newer bushings than the old crusty ones. I am cutting off the old perches as soon as I get the pinion angle set.

Re: 1973 4wd to 2wd K5 Blazer Build
 

I opened up the tank to take a look and was surprised at how great it looked. I went ahead and scuffed the bottom down and put some paint and undercoating on it. I will flip it and do the top tomorrow. I started laying out the pattern for a bolt-on notch that I will fab up this weekend. My brother has a steel fab shop so I will weld it up there.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Spent the morning pulling the 4WD frame out from under the body. Couple of tense moments but it all worked out. Any body need a lifted K5 frame for 300??

Re: 1973 4wd to 2wd K5 Blazer Build
 

Got my notch plates cut and ready to fab. I am going to bolt and weld them on.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Your gumption is admirable. 2wd k5 is on my list of vehicles to own. This is headed toward being really nice.

Re: 1973 4wd to 2wd K5 Blazer Build
 

This is my first real Square Body build. I have been mainly an Apache guy. This one is going to more for comfort and fun. I may or may not bag it in the future. Here are some before and afters of my last few builds.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Love that Apache Fleetside!!! Damn!

Re: 1973 4wd to 2wd K5 Blazer Build
 

Put a little time in today painting parts of the front suspension. I am using spray cans, but I also bake the small parts in a toaster oven for 20 minutes to cure them.
My favorite tool from Harbor Freight is the needle scaler. It will take off years of crud with ease. It is less than 20 bucks. The cross-member had 1/2" of heavy dirt on it.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Man, it's looking outstanding! Great work. Mike

Re: 1973 4wd to 2wd K5 Blazer Build
 

Got the front suspension wrapped up. I checked every nut and bolt before installing new cotter pins. It is very hard to work on suspension without the weight of the motor to help cycle the control arms. While I had everything off, I mocked up a front bag set up for later. May or may not install it at some point.
Over the next week I am going to clean up and re-install the hard lines for brake and fuel. The next big project will be the motor before I put the body on.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Getting a little bit done on the donor frame. It is ready to sell.
Got the 350 out. It will get a XE268 cam and Vortec heads soon.
Trying to decide on a transmission. I have a good 700r4, a NV3500, a TH400 and a TH350 laying around. I am leaning towards the NV3500 just because I have not had a standard in quite some time.

Re: 1973 4wd to 2wd K5 Blazer Build
 

I know it is more work than it is worth but I cleaned up all the hard lines that run down the frame. I used a surface conditioning disc and patiently did each one. They cleaned up nice considering how cruddy they were. I would rather use the factory lines than bend or buy new ones. Once cleaned, I sprayed them with clear to seal them.

I did finally get rid of the 4WD frame, and moved the rebuilt 2WD frame to the shop to work on mating them up.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Looking good, big time savings having a 2wd frame to work with, that will save you a month of fab ing frame perches etc. I did the same, reused brake lines, they polished up nice. I did a 5.7 Tbi 4L60 with 273 gears it's a nice cruzer.

Re: 1973 4wd to 2wd K5 Blazer Build
 

With the 2.73 does it actually go in to overdrive? I am wondering because my rear tires are 31" tall. On paper, I do not think a 700r4 will ever get out of third. I am probably going to use the TH400.
Love your Blazer by the way. Nice job.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Thanks for the comps....whole drivetrain was out of a 93 Caprice wagon. Definitely goes into overdrive, I still have a few bugs to work out, dash, bezel is also out of the same car, have not got the electronic speedo to work. Can't find the dash pinout for that car. Back to thinking it could be a ground wire...Your project is going to be sweet.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Do you have a picture of the surface conditioning disc you used on the hard lines? Or a brand name.

Re: 1973 4wd to 2wd K5 Blazer Build
 

CRcrft, I happen to have a lot of Sungold Brand disc. They are the Roloc type. Plenty of similar brands out there. Harbor Freight has there own brand also. Just use them lightly and they wont break through the coating on the lines. I follow up with a scuff from a Norton Scotch-brite pad and clear them. The green disc is a 3M Bristle disc. It is excellent to clean with also.

I did get the frame moved to my storage to begin the process of mating them up.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Big day today. Got the frame bolted up and rolling on its on. It was way tougher than I expected. A lot of small movements and lining it up. I will be working on the motor and tranny next. Also trying to decide if I want to bag it. I am so happy I decided to use the complete 2WD frame instead of modifying the 4WD.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Put in a little work getting the inside cleaned up. It is as bad as I thought it was. The seats hid a lot of cancer.
Luckily, the complete rear floor and wheel wells from the donor are in great shape.
I will replace the bed floor and floor boards as needed.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Something bugged me about the way the wheel sat in the wheel well. I modified the new perch to position the axle 1 inch forward. It looks correct now. I am sure I will have to order a new driveshaft anyway because I am using the TH-400 for this build. It came with the yoke still in it.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Have not had time to work on the Blazer in a while. Got it pulled home this weekend so I can put in a few hours at a time. My before and after makes it worth the frame swap.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Looks great!

Re: 1973 4wd to 2wd K5 Blazer Build
 

Seems like forever since I posted last. Got the engine pretty much done. Vortec heads with the valve guides cut down. Comp cam, lifters, springs and push-rods. All new gaskets and seals. Rebuilt Holley. Cleaning up the serpentine set-up to install. Going to tackle the transmission next. Found a guy that is willing to put it the TH400 back together for a great deal. Found some sheet metal for it. Still need a better tailgate.

Re: 1973 4wd to 2wd K5 Blazer Build
 

nice build, will be following along....;)

Re: 1973 4wd to 2wd K5 Blazer Build
 

I'm in too. The frame swap was a good idea to save lots of little headaches!

Re: 1973 4wd to 2wd K5 Blazer Build
 

Started tearing down my 700r4 for a quick rebuild. I have an ATSG book coming and all the parts I will need. It already has some upgrades and I can not wait to mate it to the motor and get it installed. Also going to put a 3.42 disc rear in to the Blazer.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Well, it took some time but I finally got the 700 rebuilt. It was not so difficult but I had a lot of online help. I followed the series of YouTube videos from Transmission Bench and was careful on each step. Luckily, I have a connected TV in my garage and could pause and rewind the couple dozen times I needed to. I added a B&M kit and used the ASTG book also. I am putting a new stall converter (1900 rpm) as per the comp cam recommendations. I ordered a new speedo gear that matches my tires and gear ratio.
On to the next phase.

Re: 1973 4wd to 2wd K5 Blazer Build
 

Added some bling during assembly :cool: