We can't determine the percentage of grade until we know how long the track from 0" to 4" will be.
Can you give us that number?
I've used the 2% incline sets and they are superb. Easily worth the small cost.
Magnus
Good stuff. I used them on the Yuba River Sub--both risers and the 2% incline. They work really well, curve to any radius you want (mine is 34-36"), and you can stack them as high as you need. The elevation on my MR is about 18" difference between the 0" at my yard to the Yuba Pass level. On some of the higher elevations, I've used a combo of 2" extruded foam and the WS risers. Works out very well. I like them. The inclines also come with a spec sheet on how to adjust gradient from 1 to about 4%. The inclines themselves come in 2, 3 and 4%, so you can mix and match all you want.
Tom
Tom View my layout photos! http://s299.photobucket.com/albums/mm310/TWhite-014/Rio%20Grande%20Yuba%20River%20Sub One can NEVER have too many Articulateds!