I've been thinking about dropping the pulley size to 3.6" on my 98 GTP for a while now, but I'm not sure if it's such a good idea. The car has been in the family for about 9 years now (parents owned it for roughly 7). It has 132,000 miles currently. What concerns me about this is that when my mom drove it, she only used regular and ran it like her GXP now. I've been running premium (where I'm at i think it's 91 octane) even since I've had it (2 yrs). This car is completely stock except for a Spectre intake I have slapped onto the TB. The fact that this car has really seen nothing but 87 octane for most of it's life makes me worry about doing this upgrade. By now anyone reading this probably could have figured that it has never been scanned for KR. I'd appreciate hearing what you guys think about this idea.