i think the spring height is 1.81" on a bigblock and if you subtract your lift of the exhaust neither spring will work because of the coil bind number.[/QUOTE
Well if he installs the spring at 1.81 and it coil binds at 1.080" it looks like he will have .730" lift before the spring binds. Should be able to go to .680 lift safely as far as coil bind.
This recommended spring, 99893, is listed as 130# at 1.850" installed height and 318# at 1.350".
