So the supposed HX35 I bought ended up being a WH1C. For all purposes it seems to be an HX35, other than drilling and tapping for a boost elbow, is this a "bolt-on" swap? It has 5 bolt holes in the rear so I think I can reuse my HY35 exhaust adapter? Has anyone done this?

The WH1C is basically the same as a HX35, think of it as the WH1C being the HX35's identical older brother. They both have the same size compressor/turbine wheels and I believe the only real difference between them is that the HX35 has map width enhancement grooves that the WH1C did not have. Also the exhaust flange from the HY should bolt right up to the WH1C as far as I know.

Awesome thanks! Now, another question. There is a small crack in the turbine housing (at the wastegate lever) and I might replace it. Upgrade to 14cm housing or keep the 12cm housing? Current HP is about 360, with a max 460 HP in the future, at least 400 HP, daily driver, don't tow that often...from what I've read the 12 spools quicker (which I want) and will support up to 450 HP. Any thoughts? Thanks.

I can't really give you any advice on what size housing to run on a 24v auto but on my 12v with the 5 speed I'm around 350hp running the stock HX35 with the 12cm housing and it spools nice for me and keeps the smoke eliminated in normal driving, however if I'm not careful I can easily push the turbo past its efficiency limit of about 35psi even with my boost elbow allowing full flow to the wastegate.