The Struggle Bus - A 70's 4x4 van build

This. The 6.2's are useless dogs.

The 6.5 turbo can be made to be serviceable. The 4BT Cummins could get the job done as well, but it is a very heavy motor. I have considered using one in a build I am playing with, but the added weight and expense vs. what I really need has left me with a gas V-8.

I don't think that 15 MPG is an unrealistic figure on flat ground with a proper tune and OD. Painless Wire Products makes a lock-up harness for the 700R4 and 4L60 that is under $100 and is pretty much plug and play.

Vortec heads are a great upgrade, just be sure you have the proper rocker arms and possibly pushrods, as well as the matching intake. Edelbrock makes a 4bbl Vortec intake. The only other change would be to pick a cam that is heavy on torque and works well at lower RPM. This will give you the most grunt when starting from a stop or rolling along in OD, and the best shot at reasonable fuel economy.

-Joe

Killer square tube tie rod.

Nice start to a mobile rape shack you have there

mmmmm free candy.

Not only is the 4BT really heavy, but it vibrates like no tomorrow. Without the right mounts you are looking at quite the shaker. That being said, it's a fantastic diesel and it's easy to get real power from. 4BT swaps . com for all your info there.

That is actually angle iron welded to the tie rods. That, I'm certain, is some sort of home brew.

My buddy calls it "Rolling Probable Cause"

If you wanted to go diesel without the weight, you could try to scrounge a VW 3.0 TDI V6.

Bugger not a 4 bolt main like my 77 G20. That thing wasn't killeable and still runs as far as I know. Keep an eye on the oil pressure, don't trust the factory gauge for that.:eek1 Low pressure/High volume oil pumps are cheap and will do wonders keeping it well lubricated.

What you should do is make sure all the valves open.....you are right in the years for the infamous GM "marshmallow" camshafts. Had three of them worn lobes, sure affected performance and MPG.:eek1And I couldn't climb the big hills so I fixed that with a new Crane cam.

Crappy little O-ring syle valve seals on them,they dry up and crumble and if the guides are worn will burn oil that way and smoke on start up. I cured mine of that....full set of O-ring valve seals then umbrella shaped ones on top of that. Studebaker parts them umbrella seals or so said the box.

Yes also had the worn Quadrajet body at the throttle shaft. Nothing that a few turns of brass shim stock couldn't fix.Fixed well enough to have reasonnable MPG and no vacuum leaks according to my gauge. But I am just one of them old guys that can diagnose valve train problems or even time an engine with a cheap vacuum gauge.

Pick & Pull junkyards will be your friend....lots of them vans at the local one, many of them with near new parts installed just before they were scrapped.

You know, I've heard mixed opinions on whether or not the four bolt is all that much better than the two. A lot of people seem to think that there isn't enough meat to sufficiently hold the four bolts without cracking, or some shit. I don't know that it's that big of an issue in this instance. I'd hate to have to swap the motor out for something like that.

My buddy mentioned something about this being a weird year for the 350. I don't remember exactly what he said about it, but it sounds like it's along the same lines as what you've mentioned. That's one of the main reasons I spent so much time crawling around underneath it, trying to find some sort of identification markings. He seems to highly doubt that this is an original motor BECAUSE of the issues that this year had. When I was fucking around with the oil pan, I was able to look up from underneath and see a few of the cam lobes, they looked fine. Well oiled and intact, but I guess you just don't really know without further digging. I plan on doing compression and leak down tests when I get around to it.

As far as the engine goes, so far I've done a plug change, seafoamed the top end, fuel system, and oil just before an oil change. Right now I've got some high mileage oil, a bottle of Marvel Mystery Oil, and a can of Engine Restore running in it. I can't say for sure that this combo is doing much, but the engine is running WAY better, and quieter, than when I first picked it up. It's got a little more pep, and the oil pressure (stock gauge) stays fairly steady. Given my limited resources at the moment, I can't think of much else to do. This is all in preparation for my ride back to Oregon in a few days.

As far as oil burning/consumption, I had several problems. An oil line was leaking (rubber crimped to steel line. Snugged up the clamps), the oil pan leaked (fixed), but I'm sure the engine still burns. When I pull the cap off the oil fill when the engine is hot, you can see some faint smoke. My buddy tells me this is blow by, or some such. Also, there is some faint smoking out of the exhaust on startup. It's all to be expected, I suppose, and has gotten a lot better after my multi-point attack with canned mechanic.

As far as your second to last comment, something about a quadrajimmy, I have no fuckin idea what you're talking about.

Kick ass project .I havnt read the thread yet , enjoyed your RRs Oh you need to do the A Team theme on it lol

The 205 T case is bullet proof , If it was me and depending on money I would switch that 350 over to TBI (ive done 4 jeeps to tbi) and maybe a 700 or 400 tranny . If not I would focus on getting a good quality cooler on that 350 trans. If the van shares the frame of the same era trucks check around the steering box , the frame cracks there on the trucks .

Any questions let me know , I bought my first 4x4 chevy when I was 13 and have played around with them ever since .I play with jeeps and the like now .



Project I did the design work on for a friend now he is building

Can you explain to me why TBI is the way to go over a carburetor? I know carbs, I don't know fuel injections. I'm trying to keep this thing simple, something I could work on on the trail, if and when the situation necessitates it. I don't want to complicate the system with electronics and all that jazz, but I admit I know nothing of TBI.

The 350 has a cooler routed and mounted in front of the radiator.

I shall check for cracks and take any preventative measures necessary to prevent frame failure. When the time comes, I plan on taking a real hard look at the frame and gusseting, bracing, and strengthening anything that looks like a weakness. It's the same approach I took to my KLR and have yet to break it... again.

I could use your input in the entire build, but after seeing those pics, I think you might be my "Fabrication guy". Bumper guards, hitch haulers, skid plates, luggage racks, etc. will need to be done. Are you up for it? Grab your crayons.

Crayons ...... sometimes I prefer google scetchup free
Its nice for drawing stuff up in 3d to get a feel for it
Idear

Reality

I don't remember if '76 was the last year for orange engines or not. I know '77s are blue. All through the 70s GM was constantly changing the emissions pack to meet regs and try to have some semblance of driveability, with each successive year more complicated than the last. Just before they went to FI, it was almost impossible to see the engine under the spaghetti mess of vacuum lines covering everything.

I think it was mostly the 305s that had trouble with soft cams. I didn't hear about the 350s doing it, but by the late 70s there were a lot fewer of those going into cars.

If the engine is really sludged up, it'll let oil pool in the heads and overwhelm the valve stem seals. I once was tasked to clean out a 350 in a mid-70s Camaro that had clogged drainback holes after only 40k miles. The owner was told she needed new valve stem seals. I discovered that the oil just couldn't get back to the pan.

I just looked at Rock Auto and the '76 has a vacuum-actuated heat riser valve on the right side exhaust manifold between the manifold and the head pipe. Make sure that it opens when the engine is warmed up or you'll cook the top end from passing all of the passenger side exhaust under the carb. It'll also kill performance and economy. If the vacuum line is disconnected I do not know if the valve is normally open or normally closed. If the vacuum motor is removed I don't know how the valve will behave when the engine is running. IMS the vacuum feed passed through a thermal vacuum switch in the thermostat housing and yours is missing.

This image has been floating through my head since I first read the thread title.


1911fan

TBI is Throttle Body Injection. The throttle body replaces the carburetor. Direct bolt on.

Sort of. You need a high pressure pump and lines for the injectors, plus sensors and all the mounting bungs for the sensors, plus the brain and wiring harness.

Okay, this part feels counter productive towards my end goal. My understanding is that it's all, for the most part, mechanical. I don't like brains.

I think that converting the fuel delivery system is the least of your concerns right now. I hate carbs and would much rather have FI. But you've got bigger fish to fry right now. Get the thing running solid enough to get you to Or, then worry about upgrades in the future.

So what does this need again. How is that rebuilt tranny running?
Seems like a new larger tranny oil cooler is never a bad thing. The passages on old coolers can get a little funky. Does 100% of the oil flow through the cooler? If yes then defiantly consider a new cooler. A generic big one + a thermo bypass for cold weather will not run you that much money.

If you want all analog fueling, stick with a carb. Keep your HEI, though. There is nothing to gain by reverting to breaker points.

The motor runs good. When I first got it, as mentioned, it seemed to need constant attendance. It ran rough, it pinged, it burned and leaked oil. I now have it running on 87 octane with no pinging, all cylinders are firing, oil leaks have been greatly minimized, and the burning has been brought down to a much more manageable level. It's still loud as all hell, but it runs solid and will squeal the tires when you mash the happy pedal.

The tranmission also seems to be running much better. It's got a small leak somewhere in the line, which is to be expected considering many of the gaskets I encountered were relatively unavailable, and thus, were replaced with half a tube of RTV (applied as directed). The shifting was rough for a while, so I went in and replaced the vacuum lines and the vacuum module. The oil cooler is relatively small, maybe 8' x 8'. I don't know that all of the oil passes through it, though. It's clean, newer, and in direct line with the air flow.

I feel confident that the engine, transmission, transfer case, axles, and drive shafts are as good as they are going to get without major rebuilds. I'm confident.