new to this site, i have a 86 gt 160,000 miles, runs very good, had it since new, all stock, need a little more grunt, found a good shop that will do rear end work, do you guys think 4.10s or 3.73 will be better then my 3.27s i have now? he recomends the 4.10s. the car rarlly see,s the freeway. next month i was thinking about the exhaust system, headers. cat back system. thanks, bob from wash. state.