[Jac Mac]

Pic from post #7 link posted by PJNSNAK/Roscoe earlier in thread. Modded pic shows where the piece of angle needs to go & front view multi coloured sketch shows pad in yellow, block blue, mount black, and mount to chassis adapter in pink. Red dots are bolt heads. Going by this pic with what appear to be correct mounts the 'angle plate' may need to be a bit thicker than 1/4", note that it should have a small upturn lug at pan end to locate mount on pad also.
Since the correct mounts will reposition & hopefully get motor central between chassis rails this should also increase room for oil filter over what you have at moment with wrong mounts. Once you get this sorted you should take the info to the kit supplier, it would be much better for them to supply this piece of hardware at their end and save future kit buyers a lot of problems, along with the correct mount part number. Even if they supplied the piece of angle iron as a loose piece.