do you want the truck to lay out? If so it's going to be some cutting. You can modify your stock control arms so that the ball joints won't bind at full compression plus add drop spindles. Air Ride Technologies makes bolt-on control arms that will let ya lay 20's - kinda pricey though. You're definately going to have to cut out your inner fenders and relocate everything that's sitting on them. Not sure if you have to tub the firewall or not.
first what year is your dime?
second here's my $.02 if your only bagin it (no spindals,arms,ect.ect..)yes they will fit
I did a drop on a friend's blazer with 20"spokes ,they look real good filling the whell wells!!!
I had the suspension bottomed out (same as bags with no other lowering components)and it drove fine ,no scrubing or anything with out taking out any wheel wells
just MAKE SURE their the right offset,and they tuck