engine fitment

this is a 65 barracuda factory 273 car, i am up grading to a 360 with a 727. the pictures show mock up only. right motor mount is still the 65 273 mount. the left motor mount is the interlocking tab style mount from a 78 dodge truck. motor sits level with car left to right. the right exhaust manifold is from a 340. the gap between the right manifold and fender skirts is tight. before i blasted the paint from the engine bay, the paint in that area was fine no charring. what can i do about this gap? any thoughts.