If the smoke clears at red-line you should be OK but play with both the boost and max fuel delivery screws to get it as clean as you can and also do service it (oil/filters etc.)...
Don't tweak the pump again now until the new exhaust is on... Exhausts make a big difference to engine breathing...
That seat mount may need a bit of welding to get a new captive nut in there... Hopefully it'll now be good enough to see a pass...