Use a table ban saw to hack off the 340 piston crown .

I have a 4" crank for my 390 build, haven't installed it yet. I was wanting to lay it in my 360 block and measure the pistons height with stock 360 pistons. Question is: would sticks of chewing gum (with the wrapper still on of course) suffice for temperary bearing spacers, if I did a good thickness measurements, add as many as you need to get 360 mains correct size. Or how about card board off back fo legal pad, cut in strips to correct thck ness . Keep in mind this is only a mockup... Unless someone out there can lathe/ mill me a set out o hardwood, then I believe i can run my 3.79" 340 crank in my 360...til the cows come home.