Re: 164 3.0 24v super
I would suggest you not try and change the belt yourself unless you have strong Alfa or mechanical experience. In my opinion, the timing belt is the car's Achilles heel. Tensioners and bearings need to be checked, replaced and adjusted accordingly. This is because, if the belt skips a tooth, it can cause the timing to be off and the valves to crash into the pistons, causing much damage.
For me, it is worth it to pay for someone with experience to do the change. On the other hand, it is expensive and it has to be done every 3 years.
Good luck the project if you go forward yourself. I am sure there are many on the board with experience on this.