The 2.80" pulley would probably grenade your engine without a tune. The norm is no more than .2" smaller than stock when still using the stock tune. The 2.8 is about .6" smaller than the stock pulley. I'm pretty sure the stock size is a 3.40". I wouldn't recommend it, but then again nobody has actually done it. If you were to try it on the stock tune, I'd say a tank of 100 octane and at least 3 ranges colder plug. But I wouldn't do it on the stock tune. The injectors are near their capacity as it sits stock. Your only hope right now for tuning is the Powerpaq from PSI-FI Motorsports or a S-AFC II. Nobody is for sure releasing any programmers for the stock PCM. We're holding out for the PSI-FI kit, then possibly purchase the DUB system from SFPH. But my hands are tied until I can get into the PCM to make changes for the big mods.