911T pistons have very small valve reliefs cut into the dome. The reason Porsche didn't specify that they were any larger, like the ones cut into the dome on the 911 Normal, 911 L or 911E pistons (the "Solex Pistons") , is that the lift and duration of the T cam didn't require the clearance.
What this tells us is that the Solex Pistons have those reliefs to keep the valves from hitting them. Therefore, you cannot use Solex cams with the T pistons, as they will hit the valves.
However, there is a bright light at the end of all this. I don't recommend re-using the original 911T pistons anyway. The last 2,0 T to roll off the line was 38 years ago, so the odds of your pistons having a top ring groove in spec are not that high. If you use new rings with the old pistons, you will get broken compression rings, just like the guy who rebuilt my 2,0 liter engine 25 years ago did, and which I detail with pictures over on the teardown thread.
Instead, you should consider using JE pistons which will facilitate a mild compression increase from the T's 8.6:1 to around 9.0:1. These can be ordered with valve reliefs to clear the Solex cams.
The most important thing to remember is if you start mixing and matching combinations of parts that were never mixed and matched by the factory you are on your own, a test pilot, a prototype engineer. If this is your first engine build you would be well advised to stick with a proven combination that will allow you to focus on the assembly operation, not on whether the parts will work together. And no matter what happens, make sure you perform the piston-to-cylinder clearance checks that are detailed in Wayne's book before you turn the engine over. This can REALLY save you money
