I just bought a new 2003 Chevrolet SSR with the 5.3 motor which has an aluminum block and aluminum heads. I normally run Mobil 1 10w-30 and AC Delco Ultra Guard Gold filters (UPF Series)in my other GM motors, a 6.0 and a 5.7. The SSR owners manual calls for an AC-PF44 filter and this size is available in the UPF Ultra Guard Gold. Does the aluminum block and head pose any difference as far as using my normal Mobil 1 10w-30 or is it the same requirements as an iron blocked motor? I plan to drain the factory oil and change the filter at 1,000 miles. Some say not to use synthetic that early but the factory Corvette motors(which are very similar to the SSR motors) come from the factory filled with Mobil 1. Any comments on this, as to what's correct, would be appreciated. Thanks.