Im building an 80 chevy silverado, long bed 1/2 ton. im putting a 6 inch suspension lift and a 3inch body lift in. i would like to atleast put 3/4 ton axles under it. I dont know what tire size i should use. no less than 35's though. im on a tight budget.and whats everyones opinion on lift blocks on the rear axle. this truck is mostly for offroad, might be on asphalt every once in awhile on a weekend or something. im putting a 383 stroker in it. not sure what my tranny and transfer case are but i think the trans is a th400. planning on putting ladder bars on the rear axle and dont know what to do for the front  anyways this is my first build on an offroad truck so im looking for advice and opinions?any would be apreciated, thanks  

You may or may not want a body lift or at least not want the 3" of body lift if you're only putting on 35's.

You said you want a stroker 383, but also are considering lift blocks? Perhaps you don't understand what they do. While they do give you lift, reasonable mild performance and are safe enough, lift blocks make your truck much more prone to axle wrap, which is bouncing up and down under hard acceleration.

You said this is mostly for offroad use and you said you were planning to put in a high-torque motor in, so if I were you I would pay the $100-300 more and buy lift springs. Personally, I would even choose good lift springs and a weaker V8, like a 305 over a 383 V8 powered truck with lift block.

I don't know a whole lot about ladder bars, but I'll take an educated guess and say ladder bars and lift blocks don't make any sense.

Hope this helps!

I agree with 'aircraftmechanic' - forget the blocks!! especially on a high lift truck. You may get away with that on a 4-inch lift if you do mostly highway and some off-road, but lift spings are the way to go in my opinion too. Yea, the blocks & ladder bars thing doesn't make sense to me either. Probably a four-link in front, I'd say.  

the ladder bars should counter act the twist caused by the lift blocks... however.. depends on what you are using your truck for... i am assuming mud.. and for that the ladder bars will be fine, but for any trail riding, the bars hang low and will cause you to get hung up.. I agree with the above though.. new springs are the way to go..  

Shackle flip on the rear would make you have to -use less of a block or enable you to get flatter springs. 14b rear would be an easy swap and are cheap to find. Look for an axle combo out of the cucv military trucks, already geared to 4.56's and a detroit in the rear, and prices have been coming down a little on them. YOu shouldn't need any ladder bar steup with the shackle flip/spring combo.  

Some stupid questions: Is a 14-bold GM a 3/4 ton axle ? and is this also a 'military truck' axle ? I though a military axle was a Rockwell axle, or is that just from a 2.5 ton, or 5 ton Army truck ? I've seen some 70's K5's at truck shows with front & rear Rockwell axles before. As I understan it, those are the top of the line when it comes to heavy duty axles. I don't remember what they were geared to.

the 2.5ton rockwells are 6.72:1 gear ratio..  as far as CUCV, military truck axles.. the CUCV is the 73-87 body style, usually 84-86 that the military used, its basically a 1ton chevy pickup.. OR a 1/2 ton blazer.  So if you are wanting the Dana 60 and 14bolt (yes it is a 1ton, though there were 3/4ton versions as well, or atleast available in 3/4 ton.  There were 2 versions, Full floater and Semi Floater.. the FF being the strongest).. go with the truck.. the blazer had 10bolts and 3.08 gears..

i forgot about shackle flips.. that would be by far the best route, it keeps the soft springs and allows decent flex.

also.. check out... www.67-72chevytrucks.com  they have a VERY active 73-87 truck board as well as a 4x4 and engine and drive train boards..

Shackle flips could work well too. (again I don't know much about shackle flips)

Just if you're buying blocks for cheap lift then buying ladders to prevent axle wrap you're wasting your money. It's cheaper to buy any kind of shackle or lifted leaf springs than it would be to buy both the blocks and ladder bars.

Is there a reason you are going with such a high lift, I run 35's on my 81 with a 4 inch lift...I did a bit of fender trimmin to make em fit....I could probably run 40's no problem, if you trim them nice you can hardly notice unless you get right up close.

I find the truck does much better all around with less of a lift and you dont have to worry about drive shaft problems etc.

Also I run a stock 350 with a little cam and carberation, 4:11s, TH400 and it seems to haul really good in the mud, if your not going into competition with it you'll break less parts, more time for fun rather than wrenchin on it all the time.

Cheers

Thanks for the info. I've been toying with the idea of upgrading my 12-bolt rear axle to a Dana 60 or GM 14-bolt. I've got the factory basic 3.08 gears, and I'd rather spend the money on a better axle that I car rebuild myself than upgrading the one I got. What's your opinion on Dana 60 vs the GM 14 bolt ? - Are the 3/4 ton 6-lug and the 1 ton 8-lug ?

Also what does 'CUCV' stand for ? ( pardon my ignorance )

CUCV is an army desigantion. There are alot of surplus axles out there to be found. The 14 bolt comes in 2 flavors, 9.5 sf that can be either six or eight lug and 10.5 ff that comes in 8 lug. The ff is the best in strength and are really cheap to buy and build w/ detroits. Downside, there are no selectable lockers on teh market for them but Arb is coming out/has come out with one, and the lowest you can go is 5.13's. The dana 60 would be my next option before the 9.5 as long as it was a ff and had the good spline counts.  

CUCV stands for Commercial Utility Cargo Vehicle

its the military designation not just army..for GM trucks and blazers..

There are many variants of the 1 1/4 ton trucks, but only one blazer type.  The blazer was more of a command vehicle hence the 1/2ton axles and 3.08 gears. Though the military overrated the trucks..

So CUCV is a Milspec rating. I'll probably have to go with the 32 spline ff Dana 60 axle since I still need to be able to street this truck at times. I'll look for a rebuildable one at a boneyard, tear it up, & re-build it myself. I think I'd be limiting myself on the type of wheels I could mount if I went the 8 lug route too. Thanks for the info.  

14b ff came in the rear of most 3/4 and 1 ton trucks for more than 15 years,... they are very streetable. There are tons of eight lug wheels out there, just look around.  

i wouldnt worry too much about 8 lug wheels.. if you are really into off roading and such, HMMWV wheels fit with some modifications to the back spacing.

Also, if you are going to put a 14bolt ff from a 1ton in your 1/2 you will need to have the spring perches moved.

there are also some write ups on both dana 60s and 14bolts in the newest issues of Four Wheeler and Petersens 4WOR..

April 06 Four Wheeler...How to build a Dana 60

May 06 Ptersens 4WOR.....14 bolt rebuild