Although intel has not published tjmax for Q6600, intel is almost assuredly using tjmax 100 for it, if they are using round numbers like 45nm tjmax.
We know intel is setting tjmax 5C above what is measured with IR at idle (from 45nm series). So it would be likely intel uses 100 on Q6600 for reason 1 the IHS measures 95 at DTS=0. And reason 2, intel has a formula for the relationship of tjmax and tcasemax, which based on 45nm tjmaxes is 26 to 30C difference for both duo and quad.
Processor--power(W)--Tcase max--Casing IR(idle)--Tjmax (actual temps are +/- few C per intel)
E7x00-------65-----------74------------------------------100
E8x00-------65-----------72.4-----------95--------------100
Q9650-------95-----------71.4---------------------------100
Q9000-------95-----------71-----------------------------100
QX9650----130-----------64.5----------------------------95
QX9770----136-----------55.5----------------------------85
Q6600 GO--95------------71-------------95-------------100?
Q6600 B3 -105-----------62.2-----------85--------------90?
E6850------65------------72-------------95-------------100?
E6700------65------------60.1-----------85?-------------90?85?
E6600------65------------60.1-----------85--------------90?85?
QX6800---130------------64.5-----------90?-------------95?
(compare to QX9650 with known tjmax)
E4400 L2--65-----------61.4----------85---------------90?85?
E4400 M0-65-----------73------------------------------100?
I am using 97 tjmax for my E8400, as 3C is graphically documented for IHS gradient at idle on pentium northwood, and intel has documented no gradient across die at idle on 65nm and I think IHS gradient is no more than 2C on 65nm from die attach improvements, and intel has stated temps are +/- a few C at tjmax.