Having spent over 8 months getting my motor built, here is my .02
Dasa is good but takes way too long to get anything done. His heads are CNC and bar none the best I have ever seen. Weller used a mic feeler and said the ports were within 1mm everywhere he could fit the gague. I went +4mm on all four valves. I like Chris at benchmark and personally used weller for my final build. If it is a family rig, go with a good 840 and call it good. Rob Muzzy may be good but I can tell you by experience that his reps that answer the phone are the worst in the world. I called twice with credit card in hand trying to buy the 916 kit and I got my butt chewed for over 30 min by some guy named Kurt because my heads were +4 valves and "Mr. Muzzy" does not go that big. He chewed me so long I had to go. I called back a week later, with credit card in hand to try again, got "Kurt" again and got another butt chewing before he told me they were sold out of all the parts for at least 8 weeks. It may be a nice kit but do you want to wait over 8 weeks if you need replacement parts? Do you have the time to sit and get your but chewed off because you have a polaris? If you call, I have been told to speak directly to Rob or hang up. I would agree.
My vote:
Weller and Benchmark. Weller is first because they are local and fast. When my motor broke a titanium spring retainer at the Parker 250 Jason had all the parts in stock to fix it and he did not charge me a dime. He went from 800 to 840 since I had to swap out one cylnder, rebuilt one head that had dropped the valve, built the motor, dyno time, etc and charged me nothing. When was the last time a motor builder stood behind their work like that when it was obviously a broken spring retainer that dropped a valve? He boxed up all the broken parts and sent them to the company that makes the spring retainers because they did not believe the damage caused by the broken retainer. Jason also has a secret to building the motor that I could not tell DASA. I will say that my weller 800 made almost 10 more hp than the DASA 840 kit on the DASA dyno when they built the exhuast. I did not tell the secret to DASA and I will not here. Just trust me, it works.
....who would you recommend as an engine builder somewhere on the west coast to put it back together...probably bigger and better?