I have a 99 GTP with almost 138,000 miles. I have a K&N CAI, a 3'' bolt-in downpipe with cat from zzperformance, I have a 180 t-stat, and I also just had my s/c coupler replaced and s/c oil changed. I already have a 3.5 pulley on the way. Is that enough to safely run the 3.5? I don't want to put too much stress on my engine considering that it has 138,000 on it already. Ive noticed that it has been leaking a little bit of oil since I had the downpipe installed and the coupler replaced. It used to leak about a year ago, it stopped when the drainplug was replaced. The car is running better than ever, I'm hoping the leak isn't related to me adding more power to the engine and its just the drain plug again. I'm an auto-detailer not a mechanic so help would be appreciated. Please let me know what you think. Thanks.