Beams are bent hydraulically with special tools. Find a shop that does this work without heat. Lowering the truck with dropped beams and coils will get you very low. If you need to get into the weeds consider a aftermarket cross member and air bags.
Seems to me that a set of drop spindles, if available, from a 1978 or earlier truck would all fit... I will have to agree that aligning the front if you use drop springs would be an issue and something would have to be done to the stock beams. Using the drop beams however will eliminate the issue, that is the whole reason for their existance. These are not the cars of the 90's where a tweak to the castor/camber or a shim here and there can make up for a cut in the springs.
Just my thoughts of course (not much room in the small processor for anything else...)
OK, here ya go. For anyone that wants to drop their ride. Different yrs are posted. I have NOT used this company, its only information passed along. Would I buy from them, sure, why not unless it was free. THis is only how one man feels about this product after beating it to death. One must make up their own mind.
I just got off the phone with a guy I've know for a while and this is what he uses. This guy burns a lot of track time (drags) and has slammed that front end down many times after the wheels have left the ground and has had NO problems with them bending. Spinle neck are strong and the springs take up most of the pounding after that - not the bars. He also admitted there are companies out there you may want to stay away from. He made NO mention of that except he didn't want to fall into that trap of slamming a company. NO future in it as he put it. Stated: "When first installed, the alignment was almost perfect on the left but the right had to be tweaked just slightly - most likely already out of alignment. He has a 3" drop all the way round. As for it not being 3" drop as advertised - false, it is. He said if the drop isn't as advertised, something else is worn out or wrong on the refit." He said the company is very willing to work with you on figuring out the problem. Hold on to your BUTT, it ain't cheap. Course what isn't.
There ya go, have fun surfing...