I was running a gmp pump and 987 hkojsing on my duster, it was running too cool. I tried a few different thermostat with no luck keeping the temp up over 170. In traffic it would creep up to about 190. I never thought I would have that problem. I started chasing a leak I thought I narrowed it down to pump leaking from the weephole. I decided if I was removing the shroud, rad, and clutch fan to change the pump I was going to do the new 440source pump, housing, and thermostat housing. The temp is more stable And now stays at 185 all the time. I can't say something was wrong with the old setup but the 440source combo is working great for me in my bb duster. They did have a problem with a restriction a while back but it has been corrected.