Is that a 17" rear wheel? Can you get the under-engine frame sections installed as is or did you have to modify them?
That is a modified ST2/4 swingarm so I am using an ST2 5.5" 17" rim and axle/adjuster assembly. The tire is a 180/55-17 and clears without any issues. The chopped and stretched ST swingarm is actually the same length as a 907 swingarm, so there are no drastic geometry changes of the suspension. The largest reason I decided on running a modified swingarm was that I didn't want to have to modify the Paso frame for the ST2 rear suspension, and this way I will not have to relocate the battery. I was leery about machining the engine cases for the Paso swingarm, and I think this arrangement will work out pretty well. I have a spare rear wheel assembly for my ST2, so the new MegaPaso 916 will use that. I obtained the ST4 engine complete with wiring harness, throttlebodies, ECU, FBF eprom, and airbox, so I'm essentially trying to shove an ST4 into a Paso chassis.
The lower frame rail bolts up on the right side with no clearance issues. I have not checked the left side, yet, though. I don't really see any issues, and if it needs to be shaved or staggered around part of the left side engine case, I'm sure I can modify one (have two sets of spare bottom rails).
What's cool about this project is that I only have about $800 in the whole thing and I have everything I need to assemble it....and some spare parts to sell to drive the cost down even further. The most costly item will be to have the bottom of the tank reshaped to clear the vertical head.