the thermostat gradually opens to the temperature at which the springs temp is  rated at. just like when you test a thermostat in a pot of boiling water, once it reaches 180 195 or what ever then the valve is completely open.  Therefore the hot water comming out of the block will only flow so fast until it reaches the temp that it fully opens.  Reason I'm arguing is that we have a 91 toyota 3.slow with the three core and it heats up just fine even in the cold ass weather we've been having.  It heats up to normal operating temperature the heater blows super hot air but yet during the summer with temperatures of over 95 degrees you can set in traffic with the air conditioner going and the temp gauge never moves.  It's worth the money IMO...

Good Post! I was just stating what i've heard and what i've seen. IMO keeping things stock are the way to go. I always seems when you get to tricky something decides to fail or blow up. thats just me though. We had a discussion in our group. your more then welcome to search and do some research. http://wattora.com/