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1979 Trans Van (appears B300 based - dually)

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Hi all,
I am about to pick up a 1979 Dodge Trans Van with a 318/A727.

For those that may be unfamiliar, these are built off a cab and chassis (this one appears to be B300 based) with a fiberglass motorhome shell on the back.
(not mine, example pic)
Automotive parking light Tire Wheel Car Land vehicle


the one that i am looking at is fully gutted minus the cab and i am in the planning stages of the project - which involves thinking of areas where improvements could be made, especially with everything currently being gone there are a lot of things that are likely simplier.

Obviously, one of the things on the list is replacing the A727 with an A500 or A518 and using hardness to control OD and lockup speeds - but that got me thinking about other improvements i can make with the 318.

Hence my visit here.

Now, this camper is a brick. a somewhat aerodynamic brick (and one of the things i'm looking at is improvements to help with that) but, there is only so much you can do - so i've made peace with the fact that this will either be fast or efficient (within reasonable expectations) but not both. given that tradeoff, i'm looking for things that i can do to help with low end torque, which should help at least to some extent with efficient.

I know that there are EFI systems out there, and/or more efficient carb setups that i could explore - as well as some 360 parts that may help like swapping valves, as well as things like aftermarket headers (edlebrock torquer headers) and i'm sure that the exhaust system could be improved.. but i'm thinking that you folks may have some input?

Thanks,

Jared
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Discussion Starter · #3 ·
I'd consider upgrading the whole powertrain to a 5.9 magnum and OD transmission. For simplicity a 93-95 van would be the best donor.
i'd thought about that - but it was not clear to me how straight forward it would be. i haven't found a writeup by anyone yet that discusses a full swap, just the trans and/or heads. i'm concerned about clearance for the exhaust and location/transfer of all of the electronics. i suppose at least the tank should be easy to find a spot for..

is the body so similar from 1970 to 2003 that i could maybe just fully transplant the dash, etc?
 

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Discussion Starter · #8 ·
The 3.9 in the vans was usually paired with the old 3 speed automatic instead of the 4 speed (OD) automatic.
It also seems the heavier vans (3500 by that time) were almost always V8 powered. The 5.9 was good for about 2 MPG on average better over the 5.2 V8.
huh, interesting. i would have expected better efficiency from the 5.2L motor, all other things equal.

I suggest not. It's a LA-based V6 with less power and torque than the late '70s LA 318 you have now. A early '90s port-injection LA 318 (aka 5.2 magnum) or LA 360 (aka 5.9 magnum), with the corresponding transmission, should be a straightforward swap.

Either way I would go for a A518 transmission.
yeah, definitely going with the A518. I saw a company that had a stand alone harness for the NAG1 and thought about investigating that, but, i don't think the "bang" would be worth the "buck"

honestly, if i were to fantasize about it, I'd go with the pentastar 3.6L and NAG 1, but i imagine it would be a serious undertaking for what would likely be relatively modest returns
 

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Discussion Starter · #10 ·
I think your money would be better put into a A518 and doing a LA 360 of some sort, even if you are putting an aftermarket TBI or port injection system on a pre-Magnum carbureted engine.
i'm definitely going to be going with the A518 - not sure about swapping anything beyond that, i guess it will depend heavily on the results i get and condition of the current 318 (doesn't run, for all i know it's blown and then a 360 becomes a no brainer)

that said, i bet i could get my hands on a 360 LA pretty cheap...
 

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Discussion Starter · #14 ·
The aerodynamic flag-style mirror was the best aerodynamic gain followed by a sheetmetal bellypan, when a car magazine did some van modifications for a report a few years ago.

It will never be particularly fast or economical. My dad had a 1979 PB200 with 5.2L & 4-on-the-floor (OD). It managed 23 mpg (highway) on trips with a family of 6.
Yeah there is a fair amount of opportunity for aero, on another forum we are investigating that.

As far as mileage, i would be THRILLED 8f i could hit 20!:D
 

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Discussion Starter · #15 ·
So ya'll got the wheels turning on a 5.2 or 5.9 magnum and trans swap and i've collected the following information so far:

- i need a 360 oil pan either way i guess?
- if i get a pre 96 magnum van nearly everything is a direct swap over for gauges etc. just get a donor and move everything
- the early magnum efi kinda sucked and i should consider either going back carb or doing an aftermarket EFI
- sounds like i have to trim some steel on the driver's side down by the magnus header, but just a little
- sounds like i want to add a timing chain tensioner while i'm in there - there are aftermarket sources?
- sounds like the mechanical fan clearance can be a pain - i planned on going electric anyhow.


couple things i'm not 100% clear on
- some talk about using the LA accessory components and covers, others talk about using the magnum ones and grinding some stuff to fit? not clear if there is a clearly better path?
- i've seen mention of the water pump from the LA but haven't read why that is important. perhaps clearance?
- if i don't have a saginaw style power steering pump i'll have to get some custom lines - but, i'm guessing i can find a saginaw style pump if i comb some junkyards. sounds like a federal pump could also bolt on correctly.
- as long as i'm using the engine AND trans, i don't have to worry about flexplate/balance (internal vs external) but i'm not clear on if i can use the same linkage or not, but sounds like i could possibly swap to a cable linkage?
- one of the threads mentioned the following: Magnum cam snout extender, or - preferably - roller cam from 89-91 LA 318 w/long snout.

i sure i'm missing more?
 

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Discussion Starter · #17 ·
Magnum EFI was basically the same throughout. Are you sure the site wast confusing the 1980’s TBI (still on an LA motor) with the true Magnums?
i am sure of NOTHING 🤣

i've done so much reading on things the last few days that i'm willing to commit to nothing more than the names dodge,318 and magnum :D
 

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Discussion Starter · #18 ·
The only real difference is that in 1996 and later they were OBDII, which is a little more complex to swap but maybe easier to hook a scan tool up.
that is good info to think about actually - cause an OBD2 port would mean that if i ended up with a RE instead of an RH i could hook up a tuner that could adjust shift points and stuff for economy.


i had a 5 star tune for my F350 focused on towing efficiency and it really did help with not getting stuck around where lockup would normally happen and holding gears a little longer, etc.

looks like 5 star only does fords, but, i'm sure that there are others out there.
 

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Discussion Starter · #20 ·
Reason the 318 does not get the mileage is when the engine is under a higher load, the air-fuel ratio drops to protect the engine. Being that the van is heavy, the 318 works harder and sits longer in the richer mode.
that makes sense. weight wise, i'm not sure where i am going to end up, it looks like the B300 curb weight was ~4900, but, i expect that the fully kitted camper was a lot more (i haven't had any luck finding specific numbers)

with the steel body removed and replaced with fiberglass and aluminum skin,in addition to being gutted i would expect a weight savings, but, who knows how much. i'm picking it up sunday so should know a lot more soon, especially if i can hit a scale on the way back.

i plan on aiming for a lot less shag, wood paneling and lighter furniture/fixtures but i'd bet i'll still be north of 6k before camper fluids.
 

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Discussion Starter · #23 ·
Good question, i don't know - I'll make sure and check it for rust.

Re: diesel yeah, i thought pretty hard about a 4bt but between the size fit and the potential noise it is not particularly high on the list.
 

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Discussion Starter · #24 ·
Has this been a Michigan (salt belt) van all its life?
Check the frame rail around where the steering box & sway link attaches to it. They had a tendency to rot out here.
There are frame repair kits if it isn't too far gone.

so, was not bad in the front at all, but, someone used great stuff as undercoat and then one of the tanks developed a leak and it rotted the frame rails out right where the rear shocks attach to the frame.. the floor and rear sub frame were totally gone. was a real shame, but, i honestly think we might've ripped it in half tugging it up on a trailer with a winch.

ah well, such is life.
 
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