This weekend I went up to Vermont in my 99 D1. I put an older fan clutch in during the winter (it was nice and quiet!) and didn't think to swap it out before I left. Well, there are a few big hills on the trip and I had several 220 spikes.

I had to blast the heat and pull over once much the the chagrin of my wife and 2 kids! Worried about the trip back I found another Hayden 2991 available locally. I put that in and it stayed pinned at the bottom line of the heat gauge the entire time! Extended uphill trails and the trip home (150 miles). Weather was the 80s and super humid the entire week.

So I cant recommend that fan enough as part of the overall heating system. It's loud at times but now I am a convert. I'm also running a 180 thermo and a flowkooler pump.