when I get up to 60km/h it feels like the tranny is slipping. now it seems to be idling rough, any tips?

 

Maintenance first. Tune up. Trans fluid/filter change, and band adjustment. Check your plenum. Take it from there.

Welcome to DF!

 

That's about 37mph american. I had a 2001 with 5.2 for a couple months last January. The torque converter would lock right around 37 to 40 mph, but would not shift to overdrive until hitting 50 mph. This was very different behavior from the 5.9 I have, which would shift into overdrive from 37 to 40 mph. Long story short is i thought i had a transmission problem, but turned out to be a broken fan clutch making a roaring sound at higher rpm's required for overdrive.

 

I bought plugs and wires, and will have tranny oil and filter changed. thanks