Usually you only want one 1/16" hole. Too many holes or too large a hole may not let the engine warm up fully. May not be a problem in CA, but in colder climates it could be. I love my 2-stage t-stat, it just works so well and the two valve make it very reliable. Still running mine from about 6 years ago:

http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

Hey dont overlook a faulty temp. sending unit in the intake. My 4runner had a mysterious problem of going into the red zone in the blink of an eye. Even after disconecting the the wire from the sending unit the guage would still read sometimes.

I eventually installed a VDO guage with the 2-stage thermostat and now I can watch it sweep from 175 to 190 degrees. Very reassuring to see your temp guage actually move, knowing that the thermostat is opening and closing

 

i did buy the 2 stage, it went up in price since you posted on your website roger.... its now $36.. i got it from Stevens Creek Toyota... they showed 1 in stock, the only other semi local place who has it in stock is santa rosa

 

I guess they did go up a little then, it was about $20 with my TLCA discount (http://www.tlca.org/). Sign up and Stevens Creek knocks at least 25% off the price of parts, you make up the $25 membership cost with $100 worth of parts in a year.

 

well its in, my truck got toasty on the inside and the guage showed jsut below the middle mark.. which is where it had always been previous to the other night....