coolant leak

[fasthawk]

freinds truck is leaking coolant.putting egr delete on it and new intake,while it was apart thinking of going with new headgaskets and headstuds truck has 135k miles on it.is their any reason to think about replacement heads with this kind of mileage thanks in advance for any input.buy the way leak is only when towing a 8000 to 10000 lbs boat with a excursion, leak is coming from overflow bottle truck runs about 225 degrees