posting clairfication

I have been following a number of threads on COE builds (customized bodies put on modern frames) but when I tried to post my next project 37 Pontiac stock modified frame and mustang running gear it was deleted, just curious on the logic. I guess neither is a period build, but why let one in but not another, I know the COE's (including me) have a following and most people don't use the stock frames or suspensions but whats the difference. yes I have read the stickys