Hi Zan500.
Your answer is NO, the 240 springs are signifiantly shorter than your 260 2+2 springs are. Should you use the 240 springs anyway the problems you'll discover will be camber settings at the rear much too negative. The 2+2 strut towers are about 1 and 1 half inch taller than the 240's plus these strut towers are thicker in overall width. Your 260 2+2 needs longer springs than found at the 240 to maintain your stock chassis height.........Now I'd suggest you use the 240's up front and go with a 280's rear spring at your 2+2 rears. Its difficult to find replacement springs for the 2+2 models I know, but its also possible to contact
www.GroundControl and get springs that while not exactly the same chasis height as stock would present correct damping and somewhat higher spring rates to prevent fenders from destroying your tires. Goodluck. shane-