Thats why I got the sirio, I was tired of messin with my 2.5. I spent more time tuning it and checking for air leaks then I did driving it. That engine took alot of the fun out of my truck.

As far as steel and alum gears, I just replaced the stockers with them every time I stripped one. It's not like all my stock gears stripped at the same time, I just don't like fixing the same thing more than once if I can help it. If something were to go wrong in the tranny with steel/alum gears, then your clutch would burn out, not your engine.

Tuning the sirio has been a dream compared to the 2.5. As long as you know the basics of what you are trying to do, it's very tuner-friendly. The reason being, IT RUNS all the time, even if it is rich or lean IT STAYS RUNNING! You can't very well tune an engine that stalls all the time. Since it stays running, you can take your time to fine tune it and make it run even better! The only problem I've had with it was at break-in. The piston/sleeve fit is so tight that the e-z start has a hard time turning it over. That problem cleared up after break-in.