Yo Mike!  You have helped me a couple of times and I don't know if this is going to help but here goes.  I am fairly new to the Toyota world however I can build and tune just about any stock or high performance Chevy, or Ford engine out there.  The first thing that I would do is check your timing marks with "TRUE" TDC.  I am sure you know how to do that but if not, the mark should be at 0. when #1  piston is at TDC with both intake and exhaust valves closed, distributer rotor facing the #1 terminal on the cap.  That means that the distributer is not a tooth off and that the crank pully is accurate.  Next, I would make sure that the distributer is "Advancing" sometimes they freeze up and need to be cleaned so that the movement is sharp and quick.  Kind of like a spring!  If everything is working properly, you should set the timing to the required spec unless something elese has been done like "Cam timing"  maybe it is off a tooth???  Dont know about Toys but these things factor into the V8 world.  And if all elese fails, set it by ear!  Just make sure that you can hear the "Ping" under load accelaration, and then just back it off a bit.  Shut it off and restart, if it stops and starts good, button it down and call it good!!!  Loud exhaust usually means that the timing is very retard,.  Hope this helps???  Hack