If you're bending the center contact spring that far, the rotor tip is probably having to jump a huge gap to get the voltage to the plug wire terminals. That will produce a terrible miss on an uphill pull once the spark plugs get a little dirty, sort of like running a 1/8" plug gap instead of .035". The height of the distributor shaft above the breaker plate is different for the tall and short cap distributors, so just swapping caps and rotors might not solve the problem.
Jerry
