Based on this pic:
It looks like the H/M valve covers are the same as the Roush style for the FE (except Roush welds the nice wire looms on the covers, a detail which adds considerable $ to the cost and is often lost by the avg. spreadsheet price comparison shopper, but I digress
).
So we know it can all fit:
Please take a side shot of the car so I can see where the sidepipes are situated vertically out the body cuts. Also, install your carb and intended air cleaner setup to record vertical space there. Finally do you have the solid bushings on the motor mounts or did they use the factory rubbers?