I'm gonna buy an HMF utility w/quiet core for my rancher. Wondering though if i should use the stock jets or a dynojet kit? maybe more power with dynojet or no? I have a UNI right now and i'm probably not going to drill the airbox, i want to leave the airbox intact. (no holes)

i know it would be a lot cheaper to buy oem jets, HMF recommends a 142 main jet and 2.5 turns for the fuel screw, I'll start there, just wondering if it's worth it power wise to buy the dynojet kit, or just buy oem and go with that

also, with a quiet core would it still be too loud for bringing it out to go deer hunting?

 

Last question first. I personally don't think it will be to loud for you with the core in. I have one on my Rincon and its not bad.
As far as jets go, You can go with the kit from Dynojet and maybe get it right, or you can use the factory jets. I've heard people complain about the Dynojets aren't drilled right. But I do know someone running their kit with success.
And yes you will need to rejet with an HMF on it. Also I would find out what size pilot jet you have now and go up one size also for a little extra bottom end. I'm sure someone on here knows what jets are in a stock Rancher. Mine was a 50 and I went to a 52 and it made a noticable improvement.