Hi Vic
Sorry to hear your problem
What kind of gasket was installed, I much prefer to the solid copper ones to the composite ones (asbestos type stuff sandwiched between thin copper sheet), I think they are more prone to blowing but will be taken to task by those who favour them
Torque settings - I use 35 lb/ft, SS will have an alloy head (right) in which case make sure the correct washers are under the head bolts, and bolts need to be tightened up in the correct order - if you don't have that info shout and I'm sure we'll get ti in a reply
Ah now the pushrod tool - it's a help in aligning the pushrods while you drop the rocker box down onto the head, rarely goes exactly to plan so be prepared to jiggle the pushrods around with a finger or bit of bent wire, meanwhile the tool will be collecting as much gasket goo as it can just to annoy you, it can be a doddle or a pain just Keep calm
yes slacken off the rockers before removing the box, makes it a bit easier, leave them wound out then you can lift the rocker onto it's pushrod and then turn it down to keep it there