They make the 3/5 drop every where for the v6. Does that one inch lower all around really need that much for weight to make it lower? That sounds kinda iffy to me man. But if they are right, I would have never believed it.
ONE OPTION TO GET THE FULL 4/6 YOU WANT IS TO BUY A 3/5 KIT (I HAVE DJM 3" CONTROL ARMS AND 5" SHACKLE/HANGERS) AND THEN ADD STOCK R/T COILS (PROBABLY FIND THEM ON EBAY) TO THE FRONT AND A 1" BLOCK TO THE REAR. R/T COILS ARE 1" LOWER THEN REGULAR DAKOTA COILS. JUST AN OPTION TO LOOK INTO.
I wouldn't think it would be any harder than the 4/6 drop. I am pretty sure in the 4/6 drop you have to cut out some notches to support your frame in the back. Buying the coils would eliminate that cutting into the frame part.
Yeah do what IBSRJOE said to do. Get a 3/5 drop from Belltech or DJM and add 1" coils/1" blocks. DON'T ADD 1" R/T coils onto that. Like you said, you have a v6. The R/T coils are made for the weight of a V8 engine, not a V6. They will more than likely lift you 1" instead of dropping you 1". Just get some 1" coils that are made for a V6 from Springtech or somehwere cheap.