I figure my Doripake will come out on the heavier end of the scale as well.
Have you ever seen anyone run the Team Suzuki Aluminum Chassis? I have been thinking of maybe making an eventual swap to that for a very stiff chassis, interested to hear your thoughts on it if you ever ran across one while in Japan.
I'm going to stick to my Yokomo aluminum drive cups as well for now, just purchased them. I'm definitely interested to see the design of the Overdose motor mount though.
The DIB chassis flex... it took me a lot of trial and error to get my DIB running decently. It drifted horribly for a while, and I got pretty frustrated. I figure your 275mm conversion has even more chassis flex? I'm still quite not happy with my setup, it can use a little more tuning, but it's real close to where I want it now. I am definitely going to try playing around with your method of body weights once I get the car a little more dialed in. I run in a tight area, so it'll be worth trying out!