Hey y'all, I have a question. I would like to build an offroad vehicle that's especially built to drive as fast and smooth as possible over hard packed dirt/clay roads or trails with huge (2-4' diameter) 3-6" deep potholes or any other deep ruts in a half-ton truck. Since what I drive on is hard, flotation is not really an issue. I think I want a locking diff. Does anyone have any suggestions about what equipment, tire size, lift or shocks might help me???  

It sounds like what you may be intersted in is a lesser version of a SCORE truck or even a dune buggy type setup.  You could go big and do a 4 link all around and use coilovers like the race guys do, have some 35's, and fiberglass bedside's and fenderwells.  Or you could do something with IFS and and a rear 4 link or even use IRS like some sandrails do.  Coilovers seem to be all the rage in high speed offroad racing.  This is because they are the spring and the shock.  I would stay a way from using a leaf spring setup if you want a smooth ride at high speeds on pothole infested dirt roads.  Something else you might consider is mounting some type of shock to your seat that way you don't feel as much of the impact when your suspension bottoms out.  I believe most SCORE, CORE, and other offroad racing rigs have them, otherwise you'd get your kidneys all beaten up. Have fun!

Scoutnut

Hey Scoutnut, thanks for your suggestions.  Does anyone have a coil or coilover rear spring conversion kit for half-ton trucks? I forgot to mention I need full use out of the stock bed. Some minor mods to the bed would be all right, maybe some fender trimming, but I need most of the cargo area and the strength of the stock steel bed. Do you have any ideas for what I could do for under $1,500 to a stock truck???(preferably under $1000)  

you can probably get the travel you need with leaf spings in the rear. do a search on desert racing trucks and find a shop that builds them or supplies parts.  i was looking into something like that for a toyota a while back and found 20" travel rear springs. the key to controlling your truck on your high speed adventures is gonna be some big piston, remote resevoir shocks like king, sway away, bilstein, or fox. hydraulic bumpstops would be a good investment if you're gonna air it out. your truck will stick to the ground when you land (like a SCORE/CORR truck) instead of bouncing a couple times like regular suspension. with long travel, soft springs, axlewrap may become an issue. you can solve that by using ladder bars. hang them from a shackle instead of mounting them to the frame. you will still maintain full travel while controlling axlewrap.  unless you plan to launch it like a freestyle mx bike, 14" of travel should be plenty. it may sound like a lot but custom leafs will be way cheaper and easier than a custom 4-link and coilovers. if you're not jumping and just need a shock to keep up with little bumps at high speed, check out the new rancho/edelbrock/bilstein/fox, etc. remote resevoir shocks advertised in the 4x mags. they're getting cheaper and everybody's making them. the ranchos are even adjustable like the rs 9000's.  

Thanks for those tips valleycat. Would those extra-travel leaf springs be available for 2wd half-tons? For remote resevoir shocks, they most companies say they are for "lifted 4x4's." Can those shocks fit on a 2wd truck if their compression and extension lengths are right? Who makes "hydraulic bumpstops?" They sound pretty cool.  

http://www.off-roadweb.com/features/0303or_fastflying/

http://www.spencerlowracing.com/products/hydraulic_bump_stop.htm

http://race-dezert.com/index1.html

http://race-dezert.com/index1.html

http://www.jeepspeed.com/index.htm

http://www.prerunners.net/home/

that should get you by for a while, there's tons of products and info for what you're looking for on the web. it's just not advertised in the mags very much. the leaf springs are made by Deaver. i couldn't find a website for them though. i'm sure you'll run across it as you research for your project.  once you find out what's available and how it will work for you, set a goal and stick to it. you could spend a million bucks buying race parts if you're not careful. a few phone calls should get you on the right track. race shops are usually pretty helpful, just tell them what you are trying to do and how much you want to spend. they're usually happy to help. they're mostly just regular guys trying to make a living. they're not rock stars or anything. and they don't try to screw you like a car salesman. good luck. it shouldn't be too long until you don't even feel those bumps.