This is not a 4x4, but thought you guys have the knowledge to help me out with some direction. Bought a fully self contained 1984 Dodge conversion van for a tow rig.... shitter and shower:) All amenties... great for 2 people. Bought it with 22k original miles, like brand new.

I am looking to get more performance out of it, especially while pulling my 3000lb rig. What should I do to get it to perform? Please list in steps by cost and performance gains.

I currently get 13mpg when not pulling and 8 mpg when towing.

I got a great deal on the van, but expected it to perform better. I just don't think it has the power to pull my rig over the Colorado mountains.

Please help with ideas.

Swap gears in the axle to 4.10 (I'm guessing you have 3.21's now) or even 3.55's will help some could also go with 3.92's..

Actually, I have 4.56 gears.... seems to be good for pulling. I suppose if I could generate enough HP and torque I could change to higher gears. I am thinking any higher at this point will definitely make it miserable.

84... hmmm, i know for the magnums all the modsare geard for hp and not low end tourqe. there are a few for the a motors tho.

get an RV cam. not as much lift so it is better for tourqe.
get a duel pain intake.
bore it out .020 or .030 if you want to go that far into it.

13 and 8, welcome to the dodge world

is the carb a thermoquad? get the q-jet replacement, ditch the stock exhaust if you dont have to worry about smog checks and give it a good going through(compression/leakdown test). do forget the little stuff like tune-up parts. 4.56 gears? no wonder your only getting 8/13 mpg.;)

yeah.... thermoquad.... I thought maybe new carb, distributor work and exhaust........ anything else? I am not sure that I am ready for any boring at this point, just hit 26k miles. Thanks for the info... keep it coming.

For a tow rig, anything that helps at low rpm is especially important. Easy to suggest lots of stuff to help make horsepower at 5-7k rpm, but do you really intend to tow at that speed? I'm guessing you'll spend most of the time in the 2-4k rpm range, so will try to focus on that.

I'm also assuming that with only 26k miles and no desire to bore, that you also don't want to stroke it. I don't think that I would either. There's a lot that can be done without messing with the bottom end, but more displacement gives more to work with. It's also a decision that needs to be made early on, because it strongly affects what other choices will be made.

Some kind of blower will give by far the most performance, and also be by far the most expensive. Don't know that anyone makes a bolt-on Roots type setup for the LA engines, but that'll give the most grunt over the widest range. Some of the centrifugal blowers like a Paxton would be easier to fit and adapt in a van. A turbo or two would be an option also; size should be matched to the operating range it'll see. Somewhere in the $2-5k range for either, I'd guess. This also should be decided early on because it also strongly affects the other choices.

From here on I'll assume that you're not going to do either the blower or stroker - if I'm wrong, then we can go back over this again.

Heads - lots of choices here. My suggestion would be the '308 castings. You may be able to find a set in a junkyard (but I doubt it) or get some rebuilt ones from AutoZone like I did ('302s are harder to find, and not available new). Mopar Performance sells new castings pretty reasonably, also complete heads, ported or not. These are the pre-magnum swirl port heads that bolt on directly but give same or maybe slightly better flow characteristics to the magnum heads. These will buy you 75-150 hp by themselves depending on level of porting and what other mods you do. Most power per buck here; and across-the-board improvement.

Exhaust - good set of long-tube headers. I've got Summit cheapies and they work well, no leaks in about a year of pretty hard pounding. Wish I'd had 'em ceramic coated, but as my neighbor says "wish in one hand and shit in the other, see which fills up first." Thorleys look pretty good also.

Cam - Mopar '759. This is a "new and improved" version of the old 340 cam; makes same horsepower but more torque due to tighter lobe centers and a little less duration. You could also go to the '761 but I think it'll be a tad too big for towing. On this one you can ask 100 people and expect to get 100 different answers. However, most other manufacturers (except Hughes) grind the ramp for small-diameter (GM-size) lifters, and the large Chrysler lifters allow a more agressive ramp to bang the valves open and closed faster, sort of like a roller allows but somewhat less so.

Carb - dunno if I'd bother on a tow rig. Thermoquads are pretty damn good when set up right. Don't think the difference in a swap could be much outside the standard error on a set of dyno pulls, maybe 5-10 horsepower at best. Maybe a little better with an intake manifold swap, but not a lot. Highly overrated in the power per dollar analysis.

Set of fast centrifugal advance springs in the distributor, a Mopar orange ECM, and a high-voltage coil. Make sure that the carb gets lots of good cold air and call it good. This should put you around 330 hp / 375 lb/ft at the flyweel.

Definitely keep the 4.56 gears.

Wow... thanks for the help. I definitely think I will do something... I just want to make it over the CO mountains. Although, my project will not begin for another few months... need to finish the house first. My goal is too keep the project from costing over half the amount it would take to do a complete engine swap or another tow rig.

Thought I would impress everyone with this wonderful piece of machinery.... call it the Shaggon Wagon.

I do appreciate the information, I will keep it handy.

Keep more coming if anyone else has an opinion. Thanks.