I have been looking at the cooling upgrades from Heath and SSDiesel for my 1996 6.5 turbo diesel. I tow a 9000 lb boat & trailer that if I try to maintain highway speeds causes the temp to rise to 210 deg. F. This makes makes me very nervous, so I slow down to 45 mph which cause the temp to lower to less than 200 deg F. Both heath & SSdiesel recommend the newer high capacity pump & fan/fan clutch replacements but SSdiesel recommends the dual thermostat coolant cross-over pipe while heath does not. Does anyone here have any experience with these cooling upgrades? Do they work for you? Which one do you recommend?

I hope they don't nuke this article:

http://maxxtorque.com/heath-diesels-65-heavy-duty-cooling-upgrade

A squeeky clean rad. is the MOST important thing to keeping the engine cool. The factory exhaust and cat also causes higher engine temps. The stock fan clutch is set too high and is always trying to catch up to the high temp. Walt [ss diesel] makes some pretty far fetched claims to his products. Heath or Kennedy are better choices. You can modify your stock fan clutch to engage earlier. As far as the single verses dual stats,some say that the single doesn't have enough capacity for the 97+ HO water pump. I've towed over 9000 behind my 92 in my sig with no cooling problems. My 95 LD would overheat with only 3000 behind it because the rad. was dirty. There are many other threads on this topic. Try a search. If you're luck you will use the right wording and will be overwelmed.

I upgraded to the 97+ water pump and dual thermostat configuration. My truck keeps it cool, even in traffic when the temp is 95F. I still need to clean my radiator, as after 14 years it is probably a bit gunked up. I also installed the DMAX fan, but haven't really noticed a difference. It could be because my fan clutch is only a heavy duty unit, not a severe duty one.

Jake

Jake, clean the rads. I got about a pound of dead bugs and small rocks out of mine; I bent the tip to my old Jet-X pressure washer to fit between the rad and A/C condenser, didn't disconnect any hoses. Recommend starting from the cooling fan and work forward, blocking the forward, next cooler with a thin piece of plywood to prevent the debris from lodging in them.(when cleaning the rad, slip the wood between the a/c cond. and the rad., then move it for the next piece)
Spray them all with simple green or such first, then let 'em soak at least 15 min. Did mine twice. Good time to clean the fan clutch thermostat, too, Spraying with PAM non stick cooking oil supposedly helps prevent mucking up so soon, but I won't try it. I put a chunk of window screen in front of the rad stack, and change it when it looks nasty. Did this with my '76 Internat, especially useful in spring, carried a roll of it.

Obtain the stock 6.5 1999/2000 waterpump (LAST 6.5 GM COOLING UPGRADE )W / SCREW ON FAN clutch & A Duramax fan blade. Heath works from a solid knowledge base so dont be afraid to go without the dual stats.Production 1996 year model trucks had the dual stats first installed in the spring of 1996.That is fairly late in the 1996 production year. .Use ACDelco or Robert Shaw thermostat.Like everyone says ,clean up the outside of the engine oil cooler,condenser & radiator. A must do first.

The upgraded cooling came out in late 96, so you may already have it. If you have the dual T-Stats, you have the HO water pump.