Hey i have an 81 toyota 4x4 standard cab pickup, i want to make it a nice trail/ offroad truck that can do some mud boggin. It has a stock engine that was rebuilt not too long ago and runs great! Willl this engine have enough power for mudd boggin? Also wat size tires should i put on it, i was thinkin about 36 inch and the lift kit that can make these tires fit. Will the axles be ok with this?
If not what kind will bolt right in with minor modifications that i can find at a junkyard or somethin? And what kinda locker will fit in the stock axle? Will an air locker fit?  

Toyota axles are not know to be weak and if you do not use a locker it should hold up well with 36's. If you use a locker it will put them in grey area in rear and danger zone up front because the birfield joints up there are not very strong. (there are after market joints out there) Also a locker up front is hard ona front axle anyway and makes steering really tuff at time and should be avoided complete except maybe a selectable locker that you can lock on demand. One important thing here, get some 5.29 gears for axles with those tires as a must have as it will help performance a lot and save driveline some stress too.  

O, yes i heard about the birfield joints. The engine is stock, will it have enough power for some mod bogs?  

O, yes i heard about the birfield joints. The engine is stock, will it have enough power for some mud bogs?  

lilkid:
O, yes i heard about the birfield joints. The engine is stock, will it have enough power for some mud bogs?

With stock gears likely not but with some 5.29's in it, it should do okay.  

We do not have much mud here in Colorado. It pretty much all runs downhill to the east and leaves us with rocks. The only really difficult mud I have ever run in was the mud pit at RTCC. That particular pit was 350 feet long, horseshoe shapped, dug 8 feet deep and filled with some 5000 gallons of water, from what we were told.
However, my understanding of the recipe for success in mud is:
1 - Light weight, since you want to float on the mud as long as possible.
2 - The tallest tires and lift you can manage, since you want to keep the undercarriage and axles out ofthe mud as long as possible.
3 - HUGE horsepower since you need tirespin to clean the lugs. Most mudders run in 4Hi, not 4Lo for this reason.
Again, you have to decide what it is you're building. A good mudder is not likely to do real well on rocks. They're too top heavy. Likewise, a good rock buggy does not do real well in mud. They're too low.
You CAN build a rig that will do really well in one and fair in the other. My Jeep is a good example, I think. It's running 37x14x15 bias IROKs on a D44 front and 12 bolt rear, with 5.13:1 gears, detroits in both ends, and spun by an injected 383 Chevy pushing through a TH350/NP-203. This rig weighs 4200lbs with a full tank and all my trail gear (straps, high lift, jerry cans, survival gear, etc) and two people in it. That is fairly light. It has tons of power. It does a great job in the rocks, and has proven itself on the toughest trails in Colorado. It does fair in the mud. My Dodge, on the other hand, is simply too heavy, at a bit over 8100lbs. It sinks like the proverbial rock. I made it 93 feet in the mud pit at RTCC. LOL
I also have to say that I disagree with Snomans suggestion that you avoid a front locker. If you're going to build a truely effective off roader, for mud OR rocks, you need lockers in both ends. Without a locker, you really only have 2 wheel drive. Rather than avoid the locker, I'd suggest you avoid the IFS (the aftermarket birfields are NOT strong enough) and either start with a vehicle that has solid axles at both ends, or chop out the IFS and put in a solid front axle.  

I do not know where the heck this "only 2wd" without lockers started!!! First off all even with open diffs they can only send the same torque to all wheels, no more no less. Next the reason I am down on detroit style (none selectable spider gear replacements) lockers in front axle is two fold. First to effectively guide you in turns you have to be able to have different wheel speeds in turns because of different rolling radius in turns. Second Ujoint in front axle are not constant velocity and the sharper you turn the more speed variation there is across the joint (it can reach 30% and more) with two speed cycle per revolution (up to 30% faster then 30% slower). Spider gear help balance this between wheel but a locker of a spool lets it stack up and leads to guide issue, steering wheel whip and broken axles, ujoints, birfields and axle stubs because the actual torque load on axle can exceed what is on wheel by 30% amd more because of ujoint when it is turned (this is why FWD cars have CV's in front not ujoints) and this leads to broken items listed above. There is only two diff styles I would have up front (three include open diff) The best choice in my book is a true trax style diff that uses a gear based LSD that plays well in a front axle because it can balance out some of the torque variations in turns caused by U joint and still give torque bias when needed while allowing different wheel speeds in turns (they have used these in OshKosh snow plow trucks for over 30 years now and they are tanks and military hummers have them too) Second choice is a selctable locker. Spider gear replacement locker have no abilty at all to power wheel at different speeds in a turn which stinks on a drive axle. Also I might add that I have been plowing snow for over 20 years and my current trucks have open diffs by choice because directional control is very important here. I have only been stuck twice in last 15 years and both times a locker or LSD would not have helped at all because all four tires where spinning anyway. I have plowed some really serious stuff in some real bad condition and where others with lockers have failed too. There is no magic cre as it is a combo of chassis, axle ratios (yes axle ratios do effect traction much to manys chagrin) tires and driver. I also have seen some ight weight vehcile swin across some mud pit that ones with big heavy V8 powered ones get buried in. Spinning to clean helps but less weight is even a bigger asset here. I have a old 2wd 27 HP tractor that weighs about 2 tons and I have got thru some mud with it on my land that would have buried many trucks because it floats on it some what with 14 inch wide and 50 inch tall drive wheels. The point of this is it is not the HP that does it but many use it to makeup for other problems rather than looking at the weight  and surface pressure issues properly as well as tread design. If I built a serious mudder it would not be a street machine and it would be light and have tractor cleat tires on it. (or I would have a set of 4 of them in back for the real nasty stuff rather than a big heavy piece of iron under the hood. Also I might add that some will argue that open diffs are good in mud somethimes because it lets each wheel feel its traction better and I think a LSD rear and a open front with right tires and low weight is the best combo for mud. Rock crawling (which I never got into) has different needs than mud)  

It's 2wd because as soon as one tire on the axle starts to spin, 100% of the power goes to the tractionless tire. That quickly equates to no-wheel drive once you have one tire on each axle spinning.
And contrary to what you post, it is not difficult to steer a locked front end. Yes, you can feel it in the steering wheel. No, it does not keep you from cornering.
I have no doubt that a LSD is the best choice for your work. But then, we're not talking about snow over pavement, are we? We are talking about bottomless mud or major rocks.  

well it is a straight axle truck, and i think if i uped the birfields, shafts, and just about th whole axle and put a locker in it (whether it be a true trac or selectable locker, etc) it would be a good all aound trail machine, remember im not triying to make a serious mudbogger or a chapion rock crawler! All i want is to be able to do some trailing!  

Make up your mind. If it's a solid axle truck, it does not HAVE birfields.  

well yes it does have birfields in the front!  

If it has birfields, then it's not a straight axle truck. Birfields are what Toyota uses instead of CV joints on their IFS suspensions.  

so if it had oh say 40 inch tires front and back, an air locker, the right gears it should be fine?  

ok we have birfield issues here. Birfields are a staight axle not INDEPENDANT FRONT SUSPENSION which uses upper and lower control arms, the birfield is a closed knucle design which means the are no universal joints. the shaft from the hub slide in the splines of the birfield, u don't believe me look int the july 2005 issue at the toyota tech 21 expert buildup tips for pick-ups and 4-runners and if that doesn't convince u contact longfield super axles.  

First things first.  Will this be a trailered rig for offroad only (trail riding, some muddin' and a little crawlin' too maybe) or is this going to be a daily driver that you want trail-ready?