In regular testing with the engine warm on a 1fz with high miles I see into 160+ psi. On cold engines I expect 10-15 lbs. One thing most people testing do not seem to take into account is the carbon build up on a piston. This will increase compression ratio(ever wonder where the pinging is coming from pulling a load on older engines).
Are you trying to figure out where the coolant is coming from? Or just trying to see if it is the head gasket? Coolant on a 1FZ can also come from the front timing cover, as well as the oil cooler. Just put some shop air to #5 with the valves closed and see if you get bubbles or air hissing in the radiator. I usually start with low pressure and increase to 80 psi max
In the long run, I have learned to use these test as a guide. but in the end, with the 1fz and its crappy original head gasket design, and carbon build up, pulling the cylinder head is more valuable to see all you need to know on what is up. Takes a few hours, but you will be light years ahead and not guessing
I know you may not know me, but I have had well over a 100 of these 1fz engines apart in the last 15 years.