Fellow SSR fanatics...I'm a car guy but a fairly new SSR guy. I have a quandary, to build on my 90K mile 5.3 or just sell it and buy an 05/06 6.0? My 5.3 has headers, K&N cold air and high flow cats other than that all stock, beautiful body and spotless interior w 90k miles. DYNO tuned producing 278RW/310 torque at @ 5500ft elevation (Albuquerque). Its a fun cruiser but compared to my other vehicles not a neck breaker in any way. All in all I prefer top end power over low if i have to choose for passing and when i can eventually take it to the AUTOBAHN!!!))) That being said I really want more low end performance while keeping relatively low rpms at highway speeds but wondering if I'd be throwing good money after bad with modifying the 5.3 any more than I have and just sell it to get a 05 or 06 with lower miles as a base to build on?? I guess my bottomline is do you all think there is enough upgrade potential in the 5.3 to still get it it up to 6.0 performance levels or into the low 400s without adding a blower? Or just enjoy as is at it already has 90K?