I just took apart the ford 9" rear that came with my 1930 Model A project. It was pulled from a 1960 ford not sure of the model. It has no vent, just one bolt holding the brass brake line splitter. The bolt hole is too small for a typical vent tube so i would just tap a larger hole for the vent. Should i install a vent tube? This car has been sitting since 1975 so i need to check every thing on the car. So the rear gear ratio is 4.57 which i think is to high. The car will be a boulevard cruiser, local car shows no long trips. The engine is a ford 289 HI PO with a 4 speed close ratio ford top loader. What is a good ratio for this set up? The tires will be about 28" tall Thanks for your help.