So I have to modify the bunks on my boat lift to accept the stepped hull of a 35' Donzi. They are currently wood (double 2X12's). Not sure if I should add material on top are cut material away with the old skil saw. Anyone do this before and can offer some advice?

My trailer has a double plank to fill the step area. The area forward of the step is single plank.

Add on top. Just countersink the screws. (use stainless steel screws)

Just did this myself a few months ago . Added layers over the existing bunks. Use a straight edge and measure you step heights to get the correct thickness. You may have to rip some 2 by's to get the correct thickness , I did . Came out great , fit perfect on the first attempt . One thing I can say is measure everything at LEAST twice . I also had to change the spacing of the bunks off center to fit the new boat . Check that too . Good luck !

Here's a couple pictures of the lift bunks for my twin stepped 292.

[ATTACH=CONFIG]528299[/ATTACH][ATTACH=CONFIG]528300[/ATTACH]

Nice, thanks everyone. I'm just going to add to the top. The Donzi has a 2-1/2" front step and a 2" rear so I'll need to raise it 4-1/2", drop it down to 2-1/2" and then straight for the rest.