The Camp 4x4 Bus - 1973 Suburban 8.1 Swap & Build

camp4x4

Adventurer
Cool build! Nice to see somebody build one since Don was hiding away from the public! A little tidbit on the cluster issue. It is NOT plug and play to put the later cluster in where the original 73 cluster came from. The big issue is the 73-75 clusters all had an Ammeter instead of a Voltmeter. Sure the later one will plug in, but you will melt that sucker down for sure wiring a Voltmeter in like the ammeter goes in.

On my old 75, the Ammeter was shot to start with. I picked up a 76-80 voltmeter off of ebay for cheap. The way I installed it was by omitting the spring tabs that connect the printed circuit to the gauge. I then added ring terminals to indivdual wires and ran one to the positive and negative side of the gauge. The positive wire ran to the fuse panel on an open port and the negative went to the ground tab just the left of the cluster on the body. Worked just fine.

The oil pressure gauge on my 75 was just like yours, mechanical. During the entire time I ran that truck I never once had a leak from it. It was just as sensitive to changes as the autometer sport comp mechanical gauge I put in my 69 Nova. Food for thought. My 91 K5 with an LS swap is using the stock gauges (electric speedo) and the only gauge that don't work right now is the dang oil pressure gauge. I've run through the GM diagnostics for it and the sending unit is the culprit. It's really personal preference.

You are moving fast for sure. Keep up the good work!

Hmmm... that's a few votes for keeping the stock cluster then. None the less, the tach would be nice to have as well, so I think I'll take you up on that gauge you've posted below. Will pm you. I'm sure it should be easy enough to adapt even if it isn't plug and play... I'll be sure to look through the wiring diagrams closely to make sure it's all good. At this point I'm thinking of replacing a fair bit of wiring already, so I've downloaded the full 73 service manual which I think should have pretty complete wiring diagrams.

Glad you like the build. Hoping to keeping making progress quickly despite the todo list continuing to grow... I have a solid plan for cleaning and painting it as it sits, which will likely take a solid week of evenings. Hopefully by the 1st weekend in June I'll be looking at starting re-assembly... ultimate deadline is a trip mid-August, but I really want to have a few shakedown runs in before then for piece of mind.
 

FBJR

Adventurer
I think it is more plug and play than you think. Tach has its own wiring anyway so you just have to address the fuel gauge.
 

Travelin _man

HEY HEY HOCKEYTOWN!!
This is a cool project!! A friend of mine has a 02 2500 HD 8.1 with an Allison transmission and he loves it. I have always been a ford truck person but those 8.1's are not joke!!
 

camp4x4

Adventurer
Woot! Just scored a 6.5L gas pedal on eBay for $75 shipped. http://www.ebay.com/itm/112414440801

WAAAAAY better than busting out almost $300 for a new one from RockAuto.

s-l1600.jpg
 

zoomad75

K5 Camper guy
Hmmm... that's a few votes for keeping the stock cluster then. None the less, the tach would be nice to have as well, so I think I'll take you up on that gauge you've posted below. Will pm you. I'm sure it should be easy enough to adapt even if it isn't plug and play... I'll be sure to look through the wiring diagrams closely to make sure it's all good. At this point I'm thinking of replacing a fair bit of wiring already, so I've downloaded the full 73 service manual which I think should have pretty complete wiring diagrams.

Glad you like the build. Hoping to keeping making progress quickly despite the todo list continuing to grow... I have a solid plan for cleaning and painting it as it sits, which will likely take a solid week of evenings. Hopefully by the 1st weekend in June I'll be looking at starting re-assembly... ultimate deadline is a trip mid-August, but I really want to have a few shakedown runs in before then for piece of mind.

Got the PM and responded. Keep up the good woork!
 

camp4x4

Adventurer
I have a suspicion you are going to regret going with an electronic throttle but that is just me :lurk:

Welp, I'm in it now... PCM and harness from Howell were already setup that way, so just gonna have to make the best of it and see.
 

mccustomize

Explorer
I think the tuning plays a big part in the throttle response as well, I have a 2003 Silverado and a 2004, both have custom tunes but the throttle response in the 2003 is a world apart from the 2004. Gearing, converter and of course intake track is going to play a part as well but I don't have a problem at all with throttle response from my 2003.
 

camp4x4

Adventurer
I think the tuning plays a big part in the throttle response as well, I have a 2003 Silverado and a 2004, both have custom tunes but the throttle response in the 2003 is a world apart from the 2004. Gearing, converter and of course intake track is going to play a part as well but I don't have a problem at all with throttle response from my 2003.

So is this just map tuning or are there other options with these PCMs? Since I don't have to worry about CARB nonsense any more I'm very curious to try more tuning I wouldn't otherwise do.

I'm also less concerned about the DBW overall since I have an auto and don't need to worry about rpm matching when shifting...

With my 37's and 4.56 gearing I'm basically back to stock final drive ratio, for what that's worth.
 

mccustomize

Explorer
So is this just map tuning or are there other options with these PCMs? Since I don't have to worry about CARB nonsense any more I'm very curious to try more tuning I wouldn't otherwise do.

I'm also less concerned about the DBW overall since I have an auto and don't need to worry about rpm matching when shifting...

With my 37's and 4.56 gearing I'm basically back to stock final drive ratio, for what that's worth.


Not real sure, I don't tune myself but I have a few friends real close to me that do, one tuned one of my trucks, another tuned they other one. I will say that the one that is less responsive has a tune still setup to protect the stock 4L60e, whereas my other truck the tune is aggressive since the trans is upgraded. I know there is a lot of trans tuning that can be done as well.
 

Larry

Bigassgas Explorer
Welp, I'm in it now... PCM and harness from Howell were already setup that way, so just gonna have to make the best of it and see.

Hehe, yeah I forgot you mentioned that. Well, carry an extra Throttle Actuator Module with you. Maybe carry a L29 7.4L mechanical throttle body and some fishing line with you too so you can always get home. The earlier electronic throttles with a separate TAC module prior to GM moving to the E38 and E78 ECM's weren’t known to be the most durable of things. The pedal feel leaves much to be desired as well but as mentioned, some of that can be tuned out and the auto trans should help buffer the herky jerkiness
 

camp4x4

Adventurer
I've been out of town most of this last week, so not much progress to show. Yesterday I did take some time to get setup for painting stuff. This is the first time I'll be using an HVLP gun, so I'm pretty excited about it. Fortunately my wife has been using one for painting various craft stuff, so we're pretty well setup for it. We only have a 2hp, 26gal compressor, but it seems to do the job well on small to medium size things. If I was painting the whole truck it'd be a different story.

I'm gonna be using Majic Paints Tractor paint and primer for all the under-body, frame and such pieces. It isn't POR-15, but my hope is that with proper prep and priming it should do just as well. It's an oil based enamel that's supposed to be pretty tough.

1030930


Oh, and I should mention that I've changed my mind about not separating the frame and body. I'm going to do it now. With the axles out and the frame and body just sitting there, it's just too close to stop at this point. I'm going to replace the body mounts anyway, so I'm gonna have to undo those bolts at some point. And that'll just make it so much easier to prep the frame and under-body for paint properly. As it sits all that needs to be removed is the gas tank and fuel/brake lines. I'd be kicking myself if I stopped so close. So there's that.

I'll be picking up a pressure washer to clean up the frame now that I can get it outside the shop. The under-body is all together pretty clean. Small patch above the transfer case got greasy, but otherwise pretty good and should cleanup nicely with a simple rag and wire brush.

Anyway, I got one of these "portable"/"temporary" car ports setup in the back area of this shop, cleaned up the ground and put the sides mostly on. Since I'm not painting anything anyone is going to see on a regular basis I'm not being super picky about sealing it and putting in the ventilators and filters and such. If a little dust blows up on my frame or crossmember I'm not gonna cry about it.

I started with the engine crossmember and 1 of the HD shackles just to see how much I suck. Turns out I don't know what I'm doing. So I let the first crap coat sit (24 hour cure time :Wow1: ) and went home to do some learning on the YouTubes. Likely I had a few problems causing the A) low coverage and B) orange peel. First, my PSI was likely way too high. I had it up around 100 because I thought I read that in the Majic Paints tips & tricks pdf. Nope. Seems it should be around 30-35psi, so I'll start there next time. Second, I really didn't mess with the dials/settings much on the gun. I should have spent more time getting the fan and quantity just right. Will do that next time. Thirdly, I'm still deciding it I want to thin it or not. I did straight primer because I had a 2.5mm tip on the gun, which should be plenty for the heavier oil paint to flow. But, I get the feeling that's not gonna help with atomization. So I've got a 1.5 on order, and my wife has a 1.4 and 1.8 I can try as well. Thinning extends the dry time, so I'm not especially eager to do that. But... yeah, will see after some tests.

Today I'm busy with Memorial Day parties, so nothing happening. But tomorrow I'll probably spend a good amount of time painting as well as tearing out the remaining pieces from the frame.

I also started poking at the rust spot on the inner fender liners from the front and it turned into a pretty big hole. :( Fortunately I found new replacements for pretty cheap at Classic Industries. $75 a piece including shipping is certainly better than trying to salvage these guys.

"Paint Booth"


Ewwww orange peel


Inner wheel well rust hole


 

FBJR

Adventurer
I have some of the same paint from TSC. It is not a rust convertor though so rust still needs to be addressed before you seal it up.

Good idea on the frame off.

Is that a HF carport??
 

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