IMO, you can't do any better than spending some time reading the SRT-6 message base on this website.

But as an SRT-6 owner myself, the biggest "preventative maintenance" type of thing I did was buying the coolant separator kit (got mine from Needswings.com -- but other people have just fabricated their own, too). From everything I read, it sounded to me like the intercooler for the supercharger of the SRT-6 is one of its "weak spots", at least in the sense that the aluminum internals expand and contract like an accordion when hot engine coolant starts circulating through it and then cools down again when the engine is shut off. Over time, it winds up cracking and leaking -- and is an expensive item to replace.

I'd much rather spend a little bit on the hoses and valves needed (even if you have to pay a mechanic another $100 or so to install them for you), and set up a separate cooling loop for the engine and for the supercharger, so the intercooler isn't thermal-stressed anymore.