64" rear spring swap eye to eye measurement of perches

[broflow]

This might be a dumb question and I am sure that there is a thread about this some where in here but I'm not very computer literate and I haven't totally figured out how to navigate this site. My question is I am swapping in a set of 64" rear springs into my blazer and I was wondering what distance I should set the perch eye to eye at? would it be 63.5 based upon the stock 52" springs perches were at 51.5. I' m running a stock rear perch modified into a flip shackle with the new shackle being 6" long. I was going to measure a new style truck like the springs came out of to see what stock was but wasn't sure if this would be a good baseline. because of the longer flip shackle. I'm guessing that I would want the shackle to be almost straight up and down without the axle hanging on the springs any advice would be greatly appreciated.

 

[muddybuddy]

ive got 64's in my k5 and i moved the front mount forward a like 2 inches and the rear mount back the rest since i wanted the axle ~1-2" moved back and the springs are 32/32 no offset like the 52's which are 26/26 no offset. do the front mount first and then determine where your rear should be, otherwise you will end up mounting it in the wrong (not optimal) spot.

do you already have the springs? i'm running ~7.5" shackle and the axle and the angle and everthing is perfect. i think the 6" shackle might be a little small, 64" springs are big, but its also where you mount it.

 

[broflow]

I've already got the springs and 6" shackle and I just got the 14bolt out of the donor truck also got all the stock perches off the my truck which is a 78. I guess the newer ones are different but it looks like just by holding the front mount up kind of stradling the body mount that it would be about 5" forward so the axle would move back 2" this would also slide the mount downward on the curve of the frame thus giving more lift which I would like to get hoping for somewhere in the neighborhood of 6-8". Ultimate goal of fitting 40" rubber under it with some fender trimming. I wouldn't mind moving the axle back a little farther than 2" though but I'm not sure what that would do to keeping the tire some what centered in the wheel well I don't really want to start changing the inner well. Any thought?

 

[muddybuddy]

if you check out the "how will your truck look with XXX" lift and XXX" tires", i posted some pics on the last page a day or two ago. its about7-8" lift and 42's with fender trimming. let me know if you need more detail or pics of where i move the mounts and what not. move the mount down the frame will give it some additional lift