Heading out...

[Treker]

This electrician is getting within retirement age and still has an adventure travel itch, usually off the beaten path with 2 or 4 wheels.

My self funded travels to Africa and Central America has been to wire schools for basic electricity and setting up clinics so traveling docs can do surgery, plus any other needs, etc. With the airlines getting tough on baggage weights and security, bringing tools and supplies have been tough, so why not drive and haul our stuff?…..sure a little crazy, but it the first lines pretty much says it all.
With that said my next trip with long time traveling companion, Doris, will be from Kansas, to at least Central America (Honduras) and possibly beyond to South America via the Pan American highway.

I need some help configuring my ride so what better group to ask the following questions of? In other words, what would you do with this equipment?

My 1979 GMC ¾ Ton, 4x4, 2” lift kit, 350 and SM465, NP205, and has new sheet metal from the last rebuild, looks like a good fit for this trip. Plus I have had her since she was born.

Add a slide in pop up camper and……

Tires / rims change from 16.5” to 17” and go modern, tall, and easier to get tires, say 285,70,17 with a highway friendly tread?

Re-build the 350 with an eye on better gas mileage and still keep a carb on it.
2 barrel or 4 barrel? Pros cons? Compression ratio to shoot for? Aluminum intake? Etc.....

Keep the headers?

Ideal cam?
With a low side in the transfer case, can I get by without a lot of bottom end torque? And still get away from a stop with the camper + weight.

A good / reliable supplier of rebuild parts for the SM465 transmission and NP205 transfer case.

All for now and thanks in advance. I hope this dialog / post is a good fit in this forum. Looking forward to hearing different ideas and getting this project going with a jump off date of early summer, 2009….


Trek

[75K30]

Welcome to the site:

You have an interesting idea, and even greater agenda. This "Trek" so to speak is for all of the right reasons, and I applaud this.

As for your journey, you will want to concentrate on recovery gear, and storing enough tools to make almost any repair roadside.

Lets start with the tires:
You have 16.5's now, and have decided to swap them out for a more common size. This is an excellent choice. Do you plan on running a steel wheel or aluminum? I only ask because there should be some thought placed here. Steel can be beat back in the case of a gian pothole, or incident.

Next would be the engine, you have a 350 now, and plan on rebuilding that. You want to keep a carb, and you are trying to build for mileage.
OK lets discuss the use of the first generation engine. Is this really worth it? IS the choice of the carb the best choice, or is there an alternative?
Where I am getting at,a nd i will come out and say it, why not change out the entire engine, and run an LS engine? These can be found for far less than one might expect, and the reliability os through the roof. They will make far more power, than your first gen engine (both in stock form) and will have mileage capabilities in the teens Something that you probably wont expect from the first gen engine. I would leam towards an iron 6.0L engine with your SM465 behind it. This would e,iminate the potential failure of the automatic transmission while on the road. You can eve upgrade you old linkage type clutch to a newer style hydraulic unit and use a 12" clutch. Stand alone computers are easy to find, and these engines are a snap to work on. You will only have to make slight mods to the fuel system to accomodate the fuel pressure required for the injection. Once you have it dialed in, it will run far longer than any carb, and with a functional closed loop system, will make changes and compensate for altitude changes and differences in fuel quality.
Speaking of fuel quality, you cant have enough fuel filters, so include extra filters into your install. Spend the bucks on quality filters, because you never know what you are getting at some roadside staions in some foriegn countries.
Alright this engine swap will leave you with the option of installing headers or not, and that is entirely up to you, but the LS engines are so efficient and make enough power that you may run stock manifolds without issue.

Depending on how much weight you are actually placiing on the vehicle will dictate how much gear ratio you will end up running. I would not rely on the 2:1 low gear of the 205 t-case, because unless you have modified the case with the "twin stick" modification, you wont be able to take advantage of the lower gear split, as this would require that you are in 4wd. Twin stick will permit the use of 2wd low range but thats a seperate issue.
Your 465 has a pretty low first gear, so this should get things motivated, and the added torque found in the 6.0L will keep thigs moving provided that you dont have a gear ratio tailored for a pass car. Total weight will determine the proper ratio.


Last but not least, the 465 and 205 re-build, There are sevreral manufacturers to chose from, but this decision might be based upon the kit that you need. I mean, hopefully you are just freshining up the boxes and they do not requre gears or too many hard parts.
More on this as this thread grows.

The t-case. You know in situations such as this, many builders will opt for a remote mount transfer case so a 2wd trans can be used, and they will mount the case in such a manner that the front and rear driveshafts will be the same length. This keeps driveline angles at an optimum angle, but more importantly only requires the driver to carry one replacement d-shaft instead of two. Driveshafts are not small, nor are they cheap, so building with this in mind usually brings this type of result.

Just throwing a couple of ideas out there, and we will see if it stimulates any conversation. Perhaps a discussion of pros and cons of each will further discussion.

Ok, pin is out of the grenade, so here goes,,,,,,,,,,

[bradrhale]

my only question is why go from the 205 to a remote mount case?? this is for the most part going to be highway for the upcoming trip. something like this upgrade might be more of a back burner project as 4wd and spare shafts will be needed on the road.
as for gear ratio, you stated you are planning on running a 285 or at least thinking about it. tire size selection will also decide on what ratio you choose.
everything else 75 stated sounds like good advice to me as in bang for your buck.

[Treker]

Thanks for the replies.

Just as I was hoping to see, things that I did not think about.

Steel rims were my choice but not for being malleable, very good point.
On the tires, a quick visit to a tire dealer and he has several to choose from.

On the 465 and 205 rebuild, there are no known problems in either. I need to replace the synchros and stop some leaks. I found a couple of on line sources for the kits.

On the engine question of why a carb...... I am in agreement on the advantages of the efi motors and you are spot on the reasons but an experience I had 2 years ago has made me inclined to sacrifice gas mileage for simplicty of repair.
I was using a old Isuzu trooper on a mountain in Honduras wiring a 2 room school that was to get a generator. I needed to run an electic drill (12 volt type) but its' battery was shot. I took the battery out of the trooper and made a 15' extension cord and patched it into the drill... worked well. After dark a local got hurt and they came to me to for a ride to a hospital 70 miles away. I put the battery back in the Isuzu and cranked away. No start, the electic fuel pump died completely... go figure....from removing the battery! coasted down the 'mountain' till we found someone with a running truck.... I felt really frustrated that I could not improvise around a electric fuel pump. A couple days later and we got the pump installed, last checked, it is still running but they won't let the battery be taken out.. lol

That was the reasoning for seeing if one can improve (to a point) the old generation engine's fuel mileage with some unknown tricks to me. Not so worried about the ecm module giving up but it's more about the support stuff. By the way I have dual 20 gal tanks....Good idea on having decent fuel filtering though.

Keep the ideas coming and many thanks.

Trek

[scavanger]

I agree with the carb. Like you said the support parts for the ECM on an LS engine could be hard to maintain in remote areas . Plus if you had to carry two of every part It could fill quite a bit of space. And two of each is what you would want. Make sure you set the truck up with two batterys. Isolate one with a relay so it is out of the system when the key is off. This way it stays charged , is there for cranking and if lights are left on you can jump the relay with the key on to get it started.
With the places you plan to drive keep it simple.

Scav.

[75K30]

Originally Posted by bradrhale

my only question is why go from the 205 to a remote mount case??

I suggested this as a consideration because of the engine, trans and t-case combo is gonna come out anyway, this remote mount NP 205 would be a piece of cake to install, and it provides many advantages. One was the use of a single spare driveshaft instead of two, and this remote mount eliminates the weak design of the chevy transfer case coupler design. You know it is a 10 spline unit, and it is probably the weakest point in any given chevy of this era. Being out in the sticks sometimes means that one has to improvise, and this often has to be done with little resources.
The remote mount case can use a typical 2wd transmission, so if failure were to occur here, and 2wd transmission could be installed, and it would not have to be the identical trans that came out. This is not possible with a married unit. I know this is far fetched, and probably overkill, but in a case like this, I might just as well be prepared for any scenario. Running the LS engine would permit any chebby bellhousing trans to be installed behind this engine, and any 2wd trans would work. Heak you could throw a 2wd th 350 in there, and it would work. Again this is not an option if the married case was left behind the 4 speed.

Ok, in the case of the failed fuel pump, we all know that this was not related to the battery removal right? I mean that would mean that the pump would be just as likely to fail when the key is turned off. Fuel pump relay changes state, and current no longer passes, and this is not any different than complete isolation similar to battery removal.
Although, fuel pump failure is probably something to consider, however the odds of an electric pump failing is probably just as likely as a mechanical one. While the mechanical pump might be easier to replace and even easier to find in the middle of Central America, the reliability of the electric pump is reasonable.
An external e;ectric fuel pump would be an easy install, and since these are external, an extra could be carried, and probably relaced in fractions of the time it wold take to change a mechanical pump.
If you were not driving through a foreign country and you were still here stateside would there even be a doubt that injection would be of great benifit? How long would one expect this injection system to last?
Given the answers I suspect were both no, then I ask would the system be more likely to fail if it was outside of the US? Again this answer is no.
This injection is a win win. You would gain MPG and horsepower, alomg with reliability. No longer is fuel injection "black magic" or some top secret stuff. It is really rather easy to get your arms around.
Heak, I see reaonable LS"X" engines for less that 2 thousand bucks complete. I mean turn key and run.
Small mods would have to be made, but these are becoming more and more popular these days
Technology is not anything to be afraid of. New vehicles are running longer, making more power, and doing it in a far more efficient fashion.

[gmctrucks]

I say by the time you get to Central America you might not have any tools with all the bandits out there and im not kidding so many people are getting kid napped or held for ransom might want to just fly over there. Sorry but just thinking about your safety.

[Treker]

I'm starting to see the light on the carb thing. So I have taken some time google'ng looking for a crate engine that will work for me. Haven't found a cheap enough one yet....

But did look at the Holley 670 cfm 2 bbl fuel injection kit. For around a grand I can get the old motor into electronics. I see these advantages in the Holley product. Too far off the mark?

Does not control the spark... I can usually fix the distributor HEI or have a spare

Uses the stock manifold so I could bolt on a carb to limp to a repair point if it goes out

Has an outboard fuel pump that will work easily with my dual tanks

Claims "improved" mpg

Anyone using one of these kits? Pros Cons?