Rread w/ interest recent articles by L Thornton & N Higgens re front spring boxes. Have the Thornton set up on my own 55 Shabby Shadow w/ lighter front springs than Thornton recc. Works pretty well but always looking to improve - Maine roads are horrible. Air holes to relieve pressure drilled in FF 15 - what size and where? I have old FF15s, new lowers. Will order new FF 15s w/ PTFF bushes - will an air vent be useful with these? Thanks, Mike Whitney