Is there any way to tell the difference? I recently picked up a Mopar reman head that was done in the late 90s. I don't want to buy new valves if I don't have to, but I also don't want to make the mistake of running TBI valves. AM I stuck replacing them to be sure? If I replace them would it behove me to pick up a set of +1 valves? What about springs? I seem to recall a lot of talk about better springs which weren't breaking the bank, but I haven't followed that.