Re: bending aluminum frames
That's one of the things I had to do to my rear mount but I had to remove about 1/2" from it before it would put my engine down low enough in my frame. You can shave off a lot from the rear mount quickly if you have a belt sander or a small mill. I milled mine down on my lathe by mounting it to the tool rest and used a 1/2" end mill for most teh cutting, then chucked in a fly cutter to finish it off nice and flat.
A belt sander will cut it down really fast too, but you'll need some welding gloves to hold it or some really good channel locks because that little piece of aluminum will heat up in your hand rather quickly trying to hold it down on a belt sander.