Want to drop my 70 CST/10

[JON70CST]

Here's what I need help with. I just bought this truck this past Friday. I love the current stance and ride height of the truck... but the problem is that the previous owner got it to sit as it is in the following picture by heating the springs :S I have had a very close look, and nothing has been damaged as a result, as he never drove it like that.

My two major short-term goals with this truck are to do the engine swap from the current 402 BBC to my ready to go 454 BBC, and replace the squashed stock springs with lowering springs, and possibly drop spindle and disc brake conversion in the front.

My question for you guys is... what kit (what size springs etc.) should I be looking at to get the truck to sit as it does now, or even lower, but properly haha. I want to keep the 6 lug rims/tires I have on the truck currently.

Thanks in advance for the help!