B18 Vtec Help Please

Hi everyone. Im using a metro subframe in a clubman. Rather than buying a frame I'm just moding my own, thing is what probleams have you all come across with clearance against things like bulk head ect ect. My main worry is how do I know that the engine is in the right place, before I make the engine mounts for it ? I'm thinking of building the suspension banging the drive shafts in & sitting it down on the deck & trying to balance everything up & see if I can get the drive shafts as level / straight as possible & then just go with that as where I will mount the engine, does this seem the correct way to go about this of am I missing something completely obvious here ? My worry is what if it's all wrong & I won't know until it's all to late & the car just isn't right ? Is there any guide out there or reference point that I can measure from ? After that everything else should be straight foreword I would have thought. Any advice would be greatly appreciated. Hèbby

Forgot to say, I'm based in Whitby, so if anyone's close & there building something similar please let me know