Answering my own question, but there seem to be two different answers in this old thread I've found...
Quote from patricks on 15.10.19 at 21:33:00:Cylinder heads BT1100, TR1, XV920r: all the same size of inlet and outlet valves
Camshaft lift: all the same cam lift
Timing: TR1 and XV920r same timing (longer than BT1100), BT1100 shorter timing
And then this reply from Nanno...
Quote from nanno on 10.10.19 at 19:24:54:They interchange, but they are not the same. XV920 should have the tallest lobes. BT1100 will have slightly milder timing and smaller lobes. XV1000 and XV1100 will have the same timing as the 920, but slightly smaller lobes.
So what would be the result of installing TR-1 camshafts in an XV920R ?
Hoping to make a decision by tomorrow, as I've found some TR-1 cams for sale.