i saw a thread a while back where guys with a thermostat were drilling some holes in the thermostat to cool the exhaust even while the thermostat was closed. what size and how many holes are you drilling in it. thx ratman

The crossover will do it's job and keep the exhaust cool but a few small 1/8 holes will help keep any steam out.
Dave

Always use a crossover with a bypass hose. The holes help to even out the temp fluctuations that occur. I use 3-3/16 holes.

start with one hole, work your way up until the results are best for you. just my .02 cents

agree with kaama start with one 3/16th and add from there real hard to refill the hole after the fact

All good stuff...These additional holes will also help keep some of the cold water coming from the crossover off of the top of the thermostat. This can cause the thermostat to fluctuate.
They also will aid " a little" with excess water pressure when the thermo is closed but that's a whole different topic
Dave

I needed 3 1/4" holes in order to keep my risers cool until the thermostat opened. But, I am running a Gil, cam driven, water pump.

Is this because you are not using a "bypass style" crossover?