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

camp4x4

Adventurer
Well, not a whole lot to report at the moment. Still getting settled into the new place, and the last few weekends have been busy with friends' weddings and other gatherings. My dad is coming out for another wrench session before Thanksgiving. I have the week off so that should be some solid progress time.

I've also definitely decided to pick up one of Northwest Fab Works' Blackbox under drive units. I've had this in mind for a while, but was initially planning to do it "eventually." However, I've got a little extra cash after selling a car, and doing the Blackbox now will solve a couple problems at once. The Blackbox will push the NP205 further away from the transmission. This will net me 2 main benefits: much better clearance for the transmission support and transfer case, and much better clearance for the actual cables of the cable shifter. At the moment theres little to no clearance between the NFW cables/mount and the 4L80e housing. I'm genuinely concerned that a cable housing may melt off allowing water and debris inside, which would be lame. Plus it makes for hella hard adjusting when everything is so tight. Besides the clearance benefits I just really like creeping up stuff... I'm certain the 8.1 could handle the lack of ratio on the NP205, but now it'll just have that much extra gearing to go with the low down grunt. :D

The one down side is that I've already made clearance in the floor for the drive line brake coming off the back of the NP205... so that'll have to get re-done with the transfer case moving backwards. Small price to pay though...

I'm also going to feel better about the amount of engagement between all the components. Previously I've had that concern with the amount of output shaft / input shaft engagement between the 4L80e and the shorter NP205 input shaft after having to put a figure-8 adapter plate between the two. Despite re-assurances that it'll be fine I still don't like how the numbers come out... with the Blackbox directly mating to both there should be plenty of engagement on either end. :D

 

FBJR

Adventurer
I like it. Will need a SYE from them soon,,,,,,,,,,,,,,,,,,,,,

I just got a solid axle for my 06 dmax and collecting parts. Plan is just simple leaf SAS.
 

camp4x4

Adventurer
Back at it! Well, finally had a fairly free day, so after doing a bit of yard work and a little bit of tidying up I was able to get on thing checked off the list and one thing almost checked off. They're little, but they're a start. It definitely is nice to be able to just go, "I'm gonna work on the truck for a bit," and walk downstairs to do it. (y)(y)

I threw a scrap bit of melamine board up on the wall so I'd have a nice visual of aaaaaaalllll the work I have left to do. So far only a fraction of what I can think of is actually on there, but it is all the things that need to be done next-ish, so I'll get those checked off and add some more as I go. The thing I checked off, "last fuel line," was pretty simple. I've had the parts for a while now, so it was just a matter of sizing the line and pushing on the twist-lock fittings. No biggie. But hey, it's done! :)



The thing I got half done was installing a new rear brake kit. I got this new line kit from East Coast Gear Supply because the old truck had soft rubber brake lines running all the way from the caliper to the junction box on the pumpkin - a quick fix I'd made a while back that has always given me the willies. I was impressed to see that the lines didn't really show any signs of damage even though they'd been on there for a few of the tougher trails I'd done before taking the truck apart. Nonetheless I've wanted proper braided banjos and hardline for a while. The ECGS kit was a little bit of a disappointment to be honest. The braided line was a little short, leaving me few options for where to mount the tab. If I'd been able to mount the tab on the axle tube, under the spring in both cases I may have had enough hardline with the kit. But as it was both hardlines were well short of reaching the junction hose. So, I got the braided banjos installed and the tab welded on, but I'll have to pick up some extra hardline in order to make it work. Oh well.



For those concerned about the bumpstop hitting the line, fear not. I'll be routing the hardline tight against the spring and perch, then along the backside of the tube, not the top, so the bumpstop will not hit the brake line.

Might be able to run down to Autozone tomorrow and pick up the brake line.. not sure if they have nicopp or not.

Anyway, I also got looking at the truck and thinking about things. One of the things I started thinking about was the air intake. Actually I've been thinking about this for a while. Now, I've seen Larry's CK5 8.1 swap guide and the post(s) he's made about the cobbled together intake he made. And while that looks nice and I'm certain it functions well, I've never really wanted to go that route. I've always wanted to figure out a way to get the intake up a bit higher than the stock location. I've thought about doing a snorkel, but I'm not a huge fan of those either. I've thought about running a pre-cleaning just on top of the hood HMMWV style. But, just tonight looking at the firewall, I'm wondering if I could run something to the cowl. Now, I've seen Jeep kit from THOR that does this and it looks pretty slick. Seems a lot of the Cherokee guys do it. There's a whole thread about some on Pirate here: https://www.pirate4x4.com/forum/jeep-cherokee/979624-cowl-intakes.html



I'm thinking that if I cut a 3" hole in the firewall between the AC box and the fuel pressure regulator...



Then put one of these 3" mounts on the firewall and connect it to an inline airbox, the rest of the tubing should be pretty straight forward. Might need a bracket to hold up the inline but I bet I could find a place to mount that fairly easily. The whole thing would run right along the side of the engine, not really in the way of anything it would seem.

61BFu7+bmoL._SL1500_.jpg 61fbsMKFreL._SL1500_.jpg

That cowl space seems to stay fairly clean and dry. Between the lip at the bottom of that space, and keeping the hole up a little... there shouldn't be much to any debris or water that gets in the intake. I could even put s little screen door mesh between the firewall and the mount to keep any significant debris out before it gets to the filter. Its pretty easy to pull that plastic bit off and vacuum out in there if need be. A little sealant on the mount and the airbox and the whole thing should be pretty water tight until water comes up over the hood in a significant amount.



So, thoughts on the intake idea? I haven't seen anyone but Cherokee owners do this... seems like a great option for the squares too...
 

bknudtsen

Expedition Leader
Hmmm... my experience is that the cowl sees a ton of water off the windshield when the vehicle is sitting, and in fact, is designed to drain water out each side and down the fender. I fear that in a heavy rain, you may just fill your entire intake with water.
 

camp4x4

Adventurer
Hmmm... my experience is that the cowl sees a ton of water off the windshield when the vehicle is sitting, and in fact, is designed to drain water out each side and down the fender. I fear that in a heavy rain, you may just fill your entire intake with water.
There's definitely a channel between the windshield frame and cowl, so I think windshield water shouldn't be a problem. I'd love to put a GoPro in there, button it all up and hit it with a hose to see just how much water actually collects...
 

bknudtsen

Expedition Leader
On my 2007 Silverado, the sunroof drains dumped out into the cowl. On each end of the cowl there were one way rubber flappers that would get clogged and everything would back up. I know it’s not a direct apples to apples comparison, but the cowl drain design hasn’t changed that much.

I would definitely do a hose test first. At least you’ve had your front clip removed, so you know the fenders are clear of debris.

And to add, your main vent intake for cabin air is on your right fender well. You may get a lot of intake noise in the cabin if the cowl and that intake area share the same airspace. Not sure if they do, just thinking out loud.

C697DFD2-C1AB-4C59-8B08-2B8CFC38DFDC.jpeg
 
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camp4x4

Adventurer
Kind of hard to see, but there's a vacuum valve up there that.... opens the fresh air? Not sure, but the path way out of the cowl area is pretty significant.



The backup would seem to occur where the main body meets the firewall, down below there's only a bit of a slit for the water to pass out of. But that'd end up being a lot of water all at once, with a helluva plug to get back up into the cowl area. And ultimately it would get into the cabin area way before.



I'm also pretty sure I'm gonna do a Vintage Air setup and ditch the capillary tube controls and all the junk in the engine bay. So.. that would leave this big hole, where the fan normally goes, empty. Vintage Air has a block off plate for it in their kits, but I could mod that to accept the intake hose plate... My guess is that would up the noise level in the passenger area though...

 

bknudtsen

Expedition Leader
If your rig is anything like mine height wise, the intake would be almost 5 feet height in the engine bay. Are you concerned that you might get that deep in water? Maybe consider running the intake back and drawing air from the rear most opening of the passenger fender?
 

camp4x4

Adventurer
If your rig is anything like mine height wise, the intake would be almost 5 feet height in the engine bay. Are you concerned that you might get that deep in water? Maybe consider running the intake back and drawing air from the rear most opening of the passenger fender?
Not so much concerned about taking on water, though it would be nice to know EXACTLY when water becomes a concern. With the stock location you're kind of guessing. The truck is pretty damn tall at this point, between the 5-ish inches of spring lift and 1" body lift.

More I'm just not a fan of the mess of bends and joints required to get the intake to the stock location by the passenger headlight. With the cowl option it seems like 2x 90* bends (one from throttle body and one to point back to the firewall) and a couple runs of tube and you're done...
 

FBJR

Adventurer
I was looking at the same idea on my 91. A small lip IFO the vent would allow water to come up and not enter. You would see it too and and have a chance to slow up a little.

Now on collecting stuff in there, wow does it!! My 91 was totally clogged. But it was sitting under lots of trees on the marin coast.

Got the rear under my 91 to flip (in for sale) but now I have to replace the tank and pump. Last registered in 05, so you can imagine how bad it ws.vacuumed valley.jpg20181016_144701_resized.jpg
 

Johnston

Observer
I have thought about same thing for my '91 square body. I have not done much research yet but was looking at riverraider.com? They have some brackets that might be useful.

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camp4x4

Adventurer
Alright... so the parts are rolling in. I got back Weds. night and of course couldn't wait to test fit the headers. Sadly, they're a no go. The long tubes are just too long. While it would appear the driver side could work after flipping the lower shackle bolt so the head was on the inside, the passenger side will almost definitely interfere with the front drive shaft. I haven't installed either the passenger side header or the front driveshaft to test, but its all just too close for my comfort. So, they're going back. :( BUT! I've got another set of shorties that a Hedman tech suggest on the way for tomorrow! :) These do seem like very nice headers, so I'm looking forward to the shorties. My 1 concern on the shorties is the driver side collector flange. It seems to kick out towards the frame a fair bit, and the suggest model is actually for the '06 Suburban the engine is from... so we'll see.

Looks good...


Frame rail clearance is great


Frame rail clearance is great


Shackle bolt clearance no good


Hangs VERY low!


Hedman 62700 Shortie 304 Stainless Headers


This evening I'll be getting after putting Hotrod Sleeve heat protection on all the fuel hoses since I'm expecting to run full dual exhausts. With the passenger side exhaust staying on the passenger side it'll be in proximity of the fuel lines. Don't wanna take any chances. May also get after finishing the rear brake hard lines since the nicopp tubing arrived.

I'm expecting the Black Box underdrive today, which I'm incredibly excited about. That'll be going on over the Thanksgiving week when my dad is out. Definitely a 4 hands and at least 2 feet kind of job to get that NP205 out and back in again.
 
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