i'm going to assume you have an automatic trans, yes, there is too much space between mounts
your currently using two sets of auxiliary mounts, whereas the bellhousing mounts on the original trans crossmember were the main motor mounts
the motor probably twists pretty good under hard acceleration and he's replacing exhaust doughnuts monthly
get some motor mounts, since the kid at autozone needs a year; get 68 chevy truck v8 motor mounts with all the bolts
buy a foot of heavy wall 3/8'' tube and a couple square feet of #10 gauge flat plate
cut the tube to bolt into the motor mount, bolt the mounts on the motor
cut some flat plate the width of the tube on one end and 2'' wider on the other
triangulate the cut plate from the top frame rail to the tube bolted in the motor mount and from the tube to the bottom frame rail
tack weld only to the tube initially, remove everything and bench weld everything, add a gusset between the plates
reinstall everything, weld the plates to the top and bottom of the frame rail; then remove the original front mounts
presto... your done
these photos show a ifs cross member, you don't have that;
but it shows the top plate from the frame to the tube bolted in the motor mount
you'll need to add a 2nd plate from the tube to the bottom frame rail and then cut the gusset