3.55s will be fine unless your looking to race the car and get every tenth out of it,and with a good convertor you can have around a 3k flash stall and it will still be tight driving around town.The start ratio with 3.55s will be 8.7 which isnt terrible,with 3.91s it would be 9.6,about 10.1 is ideal for a street car.I like to run the low first gear in the 904 which gives you the start ratio of 3.91s without the rpms on the freeway.
