best one I did was build a 2nd plate to bolt on over the original chassis plate with the motor mount holes drilled. I did that so I could reposition the servo, and other bits freely whereas when I drilled into the stock plate it was no where near as easy. Also the plate was untouched so if I felt like it I could swap it back to nitro with no visable mods

Heres pics of my one where I made a RS4 rally using a MT2 chassis plate. I based the idea off someones conversion I saw that had a bolt on manufactured conversion kit.
I since started working on making it using a RS4 EVO 3 on-road chassis(body selection/tire selection sucked seeing it was over 1/10th in size, and smaller than 1/8th), but kinda got thrown on the back burner for the past few months due to other things popping up that I found a tad more interesting.
Think when I redo it I'm going to flip the center gear around, and mount the motor on the servo side seeing the RS4 is a bit smaller my battery won't fit if I don't. When I redo it I think I'm going to flip the motor onto the servo side, rotate the center gear by 180 degrees, and either buy a battery mount off an ofna SCRT10 or something.