1985 SWB C10: Need new leaf springs?

[TopNotchSWB]

Wow the more and more I dig into this truck I find a problem. I have no idea what they did to the rear leaf springs but there is only one leaf spring on each side, it looks like they removed them and got shackles to lower it or some kind of garbage job. Now since I want to do everything right and basically do it all with good parts I was wondering what I would have to do?

If I have to buy new springs I was wondering about this website listed below and which ones would I need if I plan on going with a 5/7 or 4/6 drop with some 295/50 ,305/50, or 315/50 15x10's. Also I was thinking about putting an anti roll bar in the truck as well as some caltrac's since it would be used at the track on drag radials. What do you all think?

Also what do you all think about Competition Engineering 3 way adjustable shocks for the front? I am open to suggestions about the shocks for the back as well and was wondering if anyone is using these or just normal drop shocks.

Stock Leaf Springs from LMC:
http://www.lmctruck.com/icatalog/cc/full.aspx?Page=145
Other leaf springs from General Spring
http://www.generalspringkc.com/index...arent=45&pg=1&

Shocks
Comp Engineering 3 way's for the front
http://www.summitracing.com/parts/CEE-2615/

QA1's Front
http://www.summitracing.com/parts/HAL-RC1574P/
QA1's Rear
http://www.summitracing.com/parts/HAL-RC1574P/