Get the urethane spring isolators. Metal on metal is not a good thing on your suspension.
I was going leave mine out too and the shop that did my springs told me I would be back if I didn't leave the isolators in. I already had tears in the stock ones, so I upgraded while the springs were out.
__________________
"Ignore that whistle, it's just a vacuum leak."
2000 Mustang GT:
Saleen Series IV Twin Screw, Chicane I/C, AFCO Extreme H/E, 2.8" pulley, FMS 42# injectors, Dual Catted 2 1/2" UPR X Pipe, UPR LCAs/UCAs, 2 1/2" Flowmaster American Thunder kit, 90mm LMAF, 112" Goodyear Gatorback, Kenne Bell BAP, Mosaleen idler, T-56, Detroit TrueTrac w/ 373s, Demolet 100mm CAI, SCT XCal2 with JDM Engineering 93 Octane "Race" tune.
clap noise in front.. eibach spirngs? any ideas.. 
