I have aftermarket exchangers too and apart from the small tweak to the silencer hanger (that I had forgotten about) the Python fitted with no issues. And I’ve had it on two different engines. Have a look at the engine hangers and see if you can raise the left side and lower the right of the engine. I don’t know how the standard bumper brackets are attached to the chassis rail and the silencer hanger may need a spacer to lower it if they don’t fit like the Westy towbar brackets. But I think the biggest problem you have is the rear arch and you probably need to sort it so the front end of the silencer can go higher and the back lower to give more clearance under the bumper – I have at least 2cm between tail pipe and the bumper.
the bumper bracket it flush its the body thats wonky lol - csp suggested that the gearbox hanger needs new supports.
It’s the angle of the silencer that is wrong, it should be more horizontal so the tailpipe drops away from the bumper, but you can’t raise the front where it should be because the body is ‘wonky’.
