The 'big boys' run these all the time in their tube-frame cars.
If using a front engine mounting plate, the protruding part of the shock tower could be removed AS WELL AS the arms that hold the actual motor mount supports.

There's plenty of room and frame support for one.

Obviously, the the shock towers would be supported with the standard, but taller plate(s) welded in (following the contour of the springs (outward). This would allow plenty of room for headers in this particular area as well as providing a place to easily change the plugs.

Further, one could feasibly move the motor forward (every 1/4" counts). This too would free up some room for the collector areas of the headers.

Hmmm...maybe I'll try this on a junker (in the back of Tracy's yard) using a dummy block with good 1-3/4" tube headers.

What do you think guys?

(the pic below shows a HUGE front mounting plate. The one used for our applications don't need to be this tall or wide. It is made of 1/4" plate.

Just thankin'