If that’s all you have, spacers would work since the TQ height is shorter and the fenders won‘t line up without them, but I believe the width to be the same. The spacers would need to be solid, of course and not rubber. There are, however, structural differences to the rigid core support that have been pointed out earlier in this thread, namely the gussets. How that would impact a mix and match situation, I don’t know, but there are plenty of ridged core supports and matching stubs out there. For such a major part of the car I would want to do it right and find the correct matching parts, wether it be all TQ or all rigid.
