How to improve off-road capabilities

I live in BC, Canada. According to CarFAX my van is:
VIN 2B6HB23E5CK166294
Year/Make/Model: 1982 DODGE RAM VAN B250
Body Style: INCOMPLETE CHASIS
Engine Type: 3.7L L6 1BL OHV
Transmission: manual 3 speeds + overdrive
Manufactured In: CANADA

It is an RV conversion with 6’ raised roof.
I find it extremely reliable and tough and also very fuel efficient.

I have 2 issues though, related to its off-road and bad road capabilities and I need your advice here:

1.Problem 1 - climbing steep hills. The engine is going strong, but there are sections of some forest roads which I cannot make even in 1-st gear. Is there a way to change the gear ratios? I have some ideas, which are more like questions, rather than something that I can materialize:
• I’ve heard about a gear kits for Fords, which change 1-st and 2-nd gears, but leave the rest. Is there something like this for my Dodge?
• Or maybe I can swap the whole transmission with another from a different model? Is there any other transmission that will fit and will give me better gear ratios?
• Or I can swap the rear axle with the differential. There is a bunch of Ram vans in the local junkyard, but I have no clue what I am looking for…
• Or I can get a low gear set from a Ram pickup truck? Is there such a thing at all?

2.Problem 2 - going through dips or steeper angle changes. Because the vehicle is so long, the rear bumper often hits the ground. I would like to lift the body a few inches, but I don’t know how, where to look for parts and what parts am I looking for…

Okay...

Don't know of anything kits for the transmission, but you can change the gears in the rear. If you're really serious about going off-road, I would switch up to a 4.10 rear gear with posi-traction (or what Mopar calls Anti-Spin or Sure-Grip). You'll be able to climb trees.

There are a few things that can be done to that slant 6 to improve torque short of swapping in a V8. I won't get into the specifics, but in the late 70s the slant six was available as a Super Six, which inlcuded a 2bbl. carburetor. Try www.slantsix.org for some good info on the slant 6.


As far as lifting the van, again I don't know of any Dodge van specific kits, but you could add a set of 4" lifting blocks to the rear, but I'm not sure how you would get the front end lifted. Do you have any 4x4 shops in your area? They may be able to guide you.

Thanks Nate! Great tips.

I like the idea of swapping the differential gear, as I can achieve 2 goals at the same time - improve torque and improve the grip. Two questions here:
1. What is the stock gear ratio of my van. I tried to find out on the web and seems it is 3.55, but I'm not sure. If it really is, how much of a difference would 4.10 make? Would it not kill the highway fuel efficiency?
2. How difficult is to swap the differential gear - my understanding is that Sure-Grip will just fit in the stock casing and there is nothing special to it. But I read on the slant 6 forum that it is easier to swap the whole rear axle... and that changing the gears inside requires a lot of knowledge and special tools...Are those axles interchangeable and what model has the 4:10 ratio (I am considering here a junkyard axle).

As for lifting of the van - I see on the web some lifting blocks for the rear end, but I have no idea if they would fit, how easy is the mod and how reliable/secure is the vehicle after that.
I also found on web polyurethane coil spacers for the front end, which are inserted above or below existing coil springs. Those seem to be model specific and I can't see any for my van. I just need someone who has done this to share their experience...

As far as installing rear lift blocks, the install is pretty easy. The blocks just get sandwiched between the spring perch on the axle housing and the leaf. The van will need to be supported by the frame, so the axle housing can be lowered away from the springs.
If you are doing that, it might be easier and cheaper to get an entire axle assembly from the wrecker, than replacing the gears. I'm not sure if you are in the Lower Mainland, but Pick-A-Part has axles for dirt cheap.

Take a look at a mid-late 90's dodge Ram 4wd, they have lift blocks installed and are very easy to see. Pretty much the same thing. (I know, its not really a lift if it comes from the factory like that)

-Kent

Yes - I am in the LM and a frequent customer of Pick-A-Part. They have 3 or 4 Dodge vans there. Now that you gave me the the idea, I believe I can identify a lift block and install it.

You are right on the rear axle - I can pick one from Pick-A-Part, but I don't know how to chose the right one. My problem is I don't know what is my gear ratio and how to find out what is the gear ratio on the vans at the wrecker.

And finally if my ratio is 3.55 and I go to 4.10 what kind of difference will I feel? Is that difference (from 3.55 to 4.10) as big as the difference say between 3-rd and 4-th gears of my tranny or it is almost unnoticeable?

Your tranny has a .71:1 overdrive ratio, so at 110km/h(er, 68.4mph):
3.55 rear end - 2000rpm
4.10 rear end - 2300rpm

So really not much of a difference. It will be 15% higher engine rpm, no matter what speed.

I felt a differance going from a 3:55 to 3:92, I bet you'll feel a power improvement going to a 4:10, even with the 6 banger. It nice that u have the OD with that so gas milage wont suffer.

I think 15% difference would be just what I need, so it is worth swapping.

Can someone tell me how or where to check what is my rear axle ratio and how to tell the ratio on axles I see at the junk yard? I can't find the specs for my van... Is the final ratio stamped somewhere on the housing of the differential?

I once had a 1979 Dodge Aspen with the Super /6 in it. The two barrel made a big difference in power. However, a 1974 Plymonth Duster with a /6 would be about the same since the emission junk wasn't in it.

I would go with the 3.92 rear since it's easy to obtain and it's used in the Ram Vans too. The next engine size up is the 318cid (5.2L) that uses the 3.92 rear. Both the 3.7L and the 3.9L sixes use the 3.55.

The 3.7L is a good engine. Don't over load it any and it will last longer than the vehicle's body.

I owned a 75 dodge w/a slant 6 and I think it had the 3:23 in it.

There may be a tag on the rear end cover, or more likely u can find the rear end info on the under-hood sticker.

The other way to figure it out, I could be wrong, someone correct me if I am, but I believe u spin 1 rear wheel one complete revolution and count how many turns the drive shaft turns, mark both the drive shaft and wheel with a crayon so u have a starting point to watch it turn.

So if the wheel turns 1 time and the drive shaft turns 3.2 turns or 3.5 turns that would be the gear ratio, eith 3.23 ot 3.55.

Or is it 1 revolution of the driveshaft and count the turns of the tire, I forget, its one or the other, you'll figure it out when u try, or someone here can help clear it up.

Hope this helps