Anybody who's running an older engine (mine has 120k + miles on it), how hard is it safe to run it? I'm wondering if I coddle mine too much, e.g. I tend to upshift at around 2500 to 3500 rpm, and rarely rev past 4000 in any gear. It's a stock 8 valve, late '84 and being sorta poor I need to have the most fun, for the longest time, with the least risk of blowing it up. :) Leo