Re: Which 4 inch lift?
 

Right, well maybe you should try doing a search on shackle flips then.

So you are intentionally going to create driveline vibration or add extra expense to the project by adding a CV? :lol:

Re: Which 4 inch lift?
 

I was asking about the springs and if they were centered "originally" and you still haven't answered that...and if you don't want to or know, that's ok...i was simply asking a question. I'm trying to find out from people that actually have something similar to what i'm looking to run how things worked out from them. Probably a differant application so don't worry about it. And i have been searching the forums about the flips...which is why i'm going with it...i plan to wheel a little in this truck (like i previously stated) hence the reason i am going to correct the pinion angle of the vehicle by welding new spring perches and setting the pinion angle within 2+/- degrees of zero. I don't see how doing this would create more driveline vibration. You don't need to run a cv axle on all applications, but i've built a few trucks where that were worthy of freeway speeds and could still get good flexability when going off road without using a CV axle. I have also built driveshafts and balanced them. And i don't understand why it's a concern wether i want to replace possibly 40 year old driveshafts...i want a reliable truck, and don't need driveshafts popping out driving 60mph down the freeway. Just lifting a truck without correcting either pinion angle or the link between them isn't going to last long. I learned this the hard way way back in high school.

The only reason i responded was i'm having trouble finding a spring that's centered that i can get a couple of inches above their stock specs so that i can get a level ride height and still be able to handle small loads without sagging 6 months down the road.

Re: Which 4 inch lift?
 

OK, you are going to have to define what you mean by centered, let alone "originally." If you are trying to refer to the for/aft placement of the axle in relation to the wheel arch, then it will depend on the spring and 4 vs. 6" shackle flip combo. The flip will tend to move the axle forward, as the rotational axis is the front bushing of the rear spring. You can always use the zero rate to shift the center for/aft one inch.

As to the pinon angle, the flip in my case, on a K5, produced a -2* pinion angle which required either changing the perches, shimming too much, or going with a CV. I chose the later.

Re: Which 4 inch lift?
 

centered referring to the spring...meaning the center pin that holds the leaves together. is it equal-distant to each bolt hole. Length is measured along the top surface of the spring.

originally...meaning the stock springs...and were they centered?

i'm thinking about using this for my 67. just trying to get some information from people. There's a member here that used the flip and it moved his axle forward about an inch and a half.

and the overall lift differance between a 4.5" and 6" shackle flip is only 3/4" overall. not really that noticeable. I plan on welding new perches in and getting a nice set of driveshafts anyhow.

like i said the expense isn't the problem, but the right parts and information prior to starting the job for me is. This isn't my first rodeo, just trying to figure out these symetrics of the 67' rear springs cause the 67 & 68 rear springs are unique. Plus since i'm halfway around the world right now, i can't just run out and measure for myself so that's why i'm asking on the forums. I purchased the truck and had it delivered to my house and want parts sitting in my shop waiting on me when i get home so i can start.