i am wanting to upgrade my current corp. 10's for 14bolt rear and a 3/4 or 1 ton front axle and was wondering what i have to change under my blazer to allow for this swap. its a 91 fullsize with a 6.2L and i think a NP241 transfer case. open to any and all suggestions and ideas. Thanks

 

if you bolt in 3/4 tons they will be a direct fit. one ton the shock mounts and spring perches will have to be moved. u joints might be different too. also make sure you get the spring plates for the front axle they are different then the 1/2 ton stuff you have

 

Thanks for the help man i really do appreciate it. My other question is what would be a good gear ration for my axles.. I am running 6.2L detroit diesel and a stock 700r4 trans.

 

Depends on tire size and heighth..not sure what the stock gears are that came with the diesel version but 4.10's or lower. Probably 4.56 if you 33in+ sizes. I have yet to hear anyone talk bad about going with 4.56 gears...lots of low end power delivery but a little higher rpms at cruising speeds.

 

yeah all depends on tires. friend of mine has a 6.2 with no over drive and 4.56 gears with stock tires and that thing can barely do 55

 

I knew tire sizes was a big part of it, I am probably not going to go any bigger than 35's and I do have overdrive, thank god, and I dont think I'll set her up any higher than a 4in lift. My uncle was telling me to aim at 3.42 gears bc my peak torque and horse is supposed to be around 2800rpm and that with that ratio I'd be hitting overdrive at around the peak. Once again thanks and please keep the suggestions coming. I hope to have pics up soon as well.

 

With 33 inch tires 3.73 ratio is about as steep as yo want to go, you could use 4.11 for 35 or 36 inch tires. I think the 10 bolt front axle is the same as the 3/4 ton trucks, just the spindles out are different. You have to go back to 76 and prior to get a HD dana 44 with the good ole big hubs.
True factory 1 ton single rear ends (14 bolt) have a different spring perch width, same as duallys. BUT the dana 60 front, dually or single wheel will bolt up to a K5 blazer springs. The rear driveline will have to have the length modified to fit a 3/4 ton 14 bolt axle.

 

Thanks Burner. I just made a purchase for 3/4 ton front axle with a spool, 4.56 gears, an extra 1/2 ton front, and 4.56 gears for a 14 bolt rear for $300. I also was able to start payments on an 85 3/4 ton 2wd suburban with a full floater 14bolt rear and a 454 with a th400 for $800. Planning on stripping the doors, fenders, grille, hood and bumpers for my K5 and using whatever else I can to save money on this build. I will be FINALLY posting pics up today, a lil later. I had an offer for a Dana 60 GM front and a 1 ton rear but they wanted 1300 for it all and that was just not possible. What exactly would I be needing to do for that rear driveline, just a longer driveshaft? Once again thanks to all who have commented and i will post more later.