Yeap 1 1/2 seems to be fine. I have no noticeable power loss, I done the same as Sipp. I pulled the drain plug out the air box and tied the tank vent and crank vent into it with a threaded fitting. the diffs I just took about 8ft of hose and made a bunch of loops and poined the end back down, I do plan on getting bellows for them though. Tap a fitting into the cap of the over flow bottle for the radiator and do the same with it and some hose instead of just leaving the pin hole. That's how my triangle kit had me do the rzr 1k so I figured I better do it to the ranger also.
You need more then just a 90 on top of the snorkel. I stuck 90s on top of mine the first night I left it out (wasn't complete) but the belt housing was tied in and it rained, the belt box was full of water when I opened it. Glad I didn't have the intake tied in. I put 23 deg fittings then 90s on top of mine cause I had some leftover. 45s then 90s like on the snorkel your atv kit will work even better. and it looks good also.
I recommend silicone the air box lid closing it and letting it dry, Then take your finger and go around the outside and make sure the entire seam of the lid is filled with silicone just to be sure. I also put a layer around where the rubber boot ties the intake into the air box. Cover the threads of the fitting with silicone that you put into the drain plug hole. (Just as a not I run a 3/4in drill bit threw mine to make it the right size and a 1/2NPT fitting will screw in good and tight and seal up nice) I was a really to snorkel. Oh for the belt intake glue a fitting on a peace of 1 1/2 and the fitting will clamp nicely into the belt intake. For the belt exhaust I used a rubber 3x2 sweadge. The exhaust is held together in the middle by a lil rubber seam. I seaperated the seam so I could move it back some. I took the 3x2 and cut it down to just the cone for the 3in (right at the top where it stops getting bigger and flattens out for the 3in pipe) if you leave it hole the 3in side is to big to clamp right on the exhaust and its too long. This lets the cone slide back onto the belt exhaust till its the right size and a hose clamp tightnes it up nicely. Ill get a few more pics of mine with bed up if you want to see it.