Originally Posted by Pete
Is this engine non-interference, unlike my 944?
Yes, the 3.4s are NON-interference engines. Do not worry about adjusting the valves.
As for the timing belt, I replaced mine at 108K and it looked great. You can not adjust tension as it has an auto-tensioner. But peace of mind is worth a lot if someone else is driving it, and if it ever does go are you able to do without the truck until you get it done (i.e. tow it home, order parts, run into unexpected issue, put it back together)?
I posted somewhere around here with all the part numbers, and links.