I got a 88 K5 Blazer and recently purchased a Dana 60 and 14 Bolt rear. What kinda of problems should i look foward to?  

The Blazer also has a 6 inch lift with a 350 TBI Turbo400 NP205. I am shooting for a complete 1 Ton drivetrain and still have to rebuild both axles. I have time to figure out if there is going to be any problems installing the new axles. Any information on this would be great. Thanks for looking.  

I see no big issues. It is a shame that you have a THM400 and a 205 though because of taller low range and dated tranny. A 700R4 with a 241 with 5.13 gears would play SO MUCH better. Deeper low range and much deeper first gear too pull OD to play well with serious axle gears. And example here is with a THM 400 and 4.10 gears you first gear ratio in hi is 2.48 x 4.10 or about 10.2 to 1. In lo it is 2.48 x 1.96 x 4.10 or about 20 to 1. With a 700R4 and 5.13's in hi it is 5.13 x 3.06 or about 15.7 to 1 and in low it is 3.06 x 2.71 x 5.13 or about 42.7 to 1. More than twice as low. Plus you cruise RPM will be lower with 700R4 combo than THM 400 combo too.  Also. when you need to back out of a problem, the THM400 combo is 2.07 x 4.1 or about 8.5 to on in hi and about 16.6 to 1 in low while the 700R4/208 or 241 combo is 2.29 x 5.13 or about 11.7 to 1 in high or about 32 to one in low. (about twice the THM400 combo  There is nothing wrong with a 700R4. People that fry them do so because they use big tires with tall gear and slow bake tranny in OD. Not because it is a bad tranny. Sorry if I got off on a tangent and do the numbers but many think they are making their rig HD and powerful when they really are not. Many use 205 because they are a bit stronger and hold up better with stock gears with big tires but, if you gear axle properly and service it, a 208/241 will hold up fine plus give you far better overall gear ratios too.  

I know that the 700R4 has a lower range but why did GM put the 400 and 205 in the 1 Tons. Im going for an unbreakable setup and was wondering if the Dana 60 was going to go in alright. I see when ordering lift kits out of 4Wheel Parts there is a seperate option for 1/2Ton to 1Ton conversion. I also see that the steering setup is a little different.  

I have broken 3 np421 transfer cases in a bone stock truck with identicle gearing front and rear cracked case in half with one blip of throttle, broke the chain and sent it through the case on another unit, and completely destroyed the transfer case the third time by sliding pulling an ice shack off the lake on a trailer this winter.  All three times were under 5 mph.  with 3.28 gears torqueflight 727a and dodge 318 truck engine (full floating wrist pins). in a untouched truck all original component truck.  

I would probably run a better 2wd driveline with divorce mounted np205 because you already have an np 205. this would still keep the driveline as strong as possiblebut would prevent the same headache I'm having with an np 241. or another option could be using a doubler for a np203 to np205 this would provide even better gear reduction and the np203 planetary (available via local salvage yards)and doubling adapter is readily available (from advance adapters) for a very reasonable price. they even have a kit where you can twin stick your np 205 and run either front output only, rear output only, or true 4wd. and use the aditional gear reduction for astounding gear ratios without changing axle gear ratios. which also alleviates the problem ofg overly weak pinion gear going to a higher gear ratio causes.  

I do run more mud now that I solved my 241 blues by swapping to 3.90 gears and trading up to np 205 but the issue is do you need extreme gearing??? what are you primarily going to be running in/on pavement/ highway, sand/dirt, mud, rocks, or even hauling, consider gear ratio requirements compared to tire size being run to type of economy wanted as well as how often you will be using it offroad vs onroad, also what your engine puts out in terms of torque because vhorsepower is a near useless term in how your engine produces power because HORSEPOWER IS CALCULATED OFF TORQUE and therefor an imaginary number pulled up by a math problem. and you will find mud doesn' tend to like very low gears in transfer case but does like larger tires with 3.40to 4.10 gears in axle. rocks require more gearing for torque altogether, and I'm not sure about sand because I don't drive on it off road, but do more logging roads, where you need slower speed and torque. If the engine is built for torque guess what your horsepower will increase if it is built for horsepower your torque will suffer.  

dodgethis:
I do run more mud now that I solved my 241 blues by swapping to 3.90 gears and trading up to np 205 but the issue is do you need extreme gearing??? what are you primarily going to be running in/on pavement/ highway, sand/dirt, mud, rocks, or even hauling, consider gear ratio requirements compared to tire size being run to type of economy wanted as well as how often you will be using it offroad vs onroad, also what your engine puts out in terms of torque because vhorsepower is a near useless term in how your engine produces power because HORSEPOWER IS CALCULATED OFF TORQUE and therefor an imaginary number pulled up by a math problem. and you will find mud doesn' tend to like very low gears in transfer case but does like larger tires with 3.40to 4.10 gears in axle. rocks require more gearing for torque altogether, and I'm not sure about sand because I don't drive on it off road, but do more logging roads, where you need slower speed and torque. If the engine is built for torque guess what your horsepower will increase if it is built for horsepower your torque will suffer.

I can seen why some wheelers have Tcase issues and think they need the strongest one possible. Many are fixated on tall gears and big tires. Shear nonsense. Some run low range all the time because they cannot make it in high with gears and tires they have and they wonder why Tcase life can be a issue. Then you see silly statements like 3.40 to 4.10 gears are great in mud so you can run low range and then they wonder why Tcases can fail. If you have the right axle ratios for your tires and engine in mud, you will not even need low range and be able to get better tire speed when needed. Nor do many understand the torque reaction from tall gears in chassis twist or its effect on traction. Deeps gear provide less axle/chassis twist which means better traction (torque wanting to lift RR and LF and this is why RR ALWAYS spins first going forward in a open diff) Your axles are your strongest reduction units, not your tranny or Tcase. Use them wisely yet this seems to escape many as they try to reason away the need for deeper axles. There was a time when old trucks came with 4.10 or 4.56 from factory with 4x4 and no OD and with stock tires the drive line was bullet proof. Then they added taller axles and OD and increased drive line loading to get same torque to ground and then someone lifts them and torque loads go throw ceiling if axle gears are not changed. There is a very simple rule of thumb here. Take your tire size and divide it by you axle ratio and if you want good power and good cruise with a OD tranny you want a result of about 7.2 (example 30 / 4.10 = 7.31) If you want max possible ground power and traction shoot for about 6.6 (example 30 / 4.56 = 6.57)  This means that is you have 35's you want 4.88 to 5.13 gears (result is 7.17 to 6.82) and with 38's 5.38's (7.06). OD opens up a whole new world for gearing possibilities that many ignore. Also there is nothing imaginary about HP as suggested above. HP is a measurement of work being done and it is the result of torque x RPM /5252. Using this you can accurately calculate how much HP your engine is making at any given RPM if you know its torque output at that RPM or you can modify equation to figure out how much torque you need to make "X" amount of HP at a given RPM. Many tend to think gee, I have a 380 HP crate motor so I have 380 HP all the time. The problem with this is that to get high peak HP you need to move torque peak to a higher RPM (a trick they have been doing since the early days of racing) but then you actually make less usable HP at lower RPM's because torque is down as well as efficiency and MPG. What this means if wheelers would use their head and crunch some numbers they could build some strong rigs with proper power curve and that do not eat Tcases, drive shafts or trannies  and will not need a push and/or a downshift on a interstate hills either. BTW, the THM400 was a great tranny in its hey day but that day is gone. It was born when BB motors  and 400 ft lbs plus torque were the norm in family cars. WIth the extremely high engine torque the THM400's very limited ratio range was not a big problem and cars rolled well and rarely rode stall. Now enters the 4x4 world and with the limited ratio range of a THM 400, you limit your effective low gear ratios if you are worried about cruise RPM and performance suffers. The more gears in tranny they better (less is not better) Why do you think semi's have 13 speeds and more? it is because they can have good startout power AND keep engine in power curve as it gains speeds so rated HP is basically available all the times. A 4 speed automatic with proper gears in axle is going to make your HP more usable and avoidable than any 3 speed ever will.  

don't go with the 700r4. its too weak to handle the stress of off-roading. snoman do you even know what stall is? i am not trying to be a jerk just curious. if you want bullet proof stay with your current set up  

1978k-20:
don't go with the 700r4. its too weak to handle the stress of off-roading. snoman do you even know what stall is? i am not trying to be a jerk just curious. if you want bullet proof stay with your current set up

A converter is riding the "stall" when the output speed is lower than input speed and it reaches full stall ratio when at a stand still and then ratio decreases as speed increase until RPM is high enough that no more fluid "reduction" is taking place. (usually around 2300 to 2400 RPM on a stock converter) The problem is the while on stall you are making a lot of heat as fluid is compressed and redirected through turbine blades to multiply torque at a lower output speed and this heat kills. As far as a 700R4 there is nothing wrong with them at all. I have one 18 years old with 180K plus miles on it and it works great and it has towed and been across rockies more than a dozen times too. What kills 700R4 is people that lift truck run tall gears and then force 700R4 in stall range in upper gears a lot and slow bakes tranny. The really silly part is that you want to cling to a old THM400 as the tranny of choice when a 700R4 has a deeper first and a wider ratio range of about 4.3 to one (from highest to lowest gear) and the 400 is only 2.48, THe net result is that you can run 30% deeper axle gears than you can with a THM400 and still have same or lower cruise RPM and have 60% MORE power in first gear because of combo of lower first gear and deeper axle AND 40% more power in reverse (deeper reverse and deeper axle) So go ahead, think inside the box rather than outside it and handicap your trucks potential and stay with old and dated hardware and thinking.  

ever tore a 700r4 apart? if you haven't you should. i have nothing against running an over drive transmission as long as its not the 700r4. never had good luck with them. stall speed depend on if the engine is a big block or small block. factory stall is a little closer to 1800 rpm.  

There are two stalls on a tranny. (actually three because there is a flash stall too when you suddenly jump on converter quickly but we will not talk about it here) One is at stand still and the other when it is in motion but output shaft speed is still well below input speed. This secondary "stall" is usually about 400 to 500RPM or so above stationary/static stall. BTW, the 4L80 in my 2000 K3500 that came with a dual stator converter (dual stator can give up to 3x torque increase at static stall vs 2 to 1 or so for stock single stator ones) will stall at about 2000 RPM static. GM used dual stator converters with 4L80 in HD apps.  

right but we are not talking about the newer trucks. the older trucks had a lower stall to get off the converter as soon as possible.  

1978k-20:
right but we are not talking about the newer trucks. the older trucks had a lower stall to get off the converter as soon as possible.

Still had two stalls though...  

Well, I had my share of problems swapping axles, but doesn't have to be that way. First my donor truck was a cab and stake bed chevrolet truck, meaning it was a dually truck. I had to change the front hubs on my 60 cause they were off set for a dually wheel. Also had to change the wheel studs and drill out the holes in the rotors. After that it simply bolted on. Have to use the spring plates for the sixty as well as u-bolts. Steering hooks up and so does brakes no problem. Now rear axle, again using 14 bolt from same donor truck was to narrow! So I went to the junk yard and pick another 14 bolt up from a srw one ton crew cab chevy. I had to re-index the spring perch for my purpose(high pinion angle), but it would have bolted right up, brakes and all except emergency brakes in some case. Had to use a spicer change over u-joint. With all my mistakes the swap cost me $1600. That didn't include ring in pinion swap and front axle rebuild for my application... that's about another fifteen hundred.  Oh, and I would go with a th400 divorced transfercase, or th400 np205 combo... Ran the 700r and np 208 and burned up transmission once before I change it to curret th400 and np208. No problems yet.