It may not be pretty but if you can , leave it there .
The stiffer your frame the better your truck will handle with your suspension setup .
As stated you can cut holes where need be to run exhaust and brake lines etc .
Just make sure you cut round holes and not square holes , as the corners of square holes give places for cracks to start .

 

The troubles are mostly self inflicted , but my errors began by using a 302 with the aod to make my mounts " same block right " and set it as low as possible . While assembling the 408 engine I found that the oil pan is not interchangeable and that the 351 has a substantially deeper pan making a 2+ " lift necessary . This in it self is not a disaster but has gone down the line . With the lift , the taller deck and the tall valve covers my booster no longer fits so must be moved to the other side of the steering column , pedal needs to be remade , have made my second trans mount , exhaust now aims into the X frame and stainless does not bend well , the trans now hits the fire wall and trans cover and I'm not entirely sure of the drive shaft clearance though the X frame . I may be overreacting if the driveshaft will clear the only problem solved by removing it will be the exhaust , all others are there to stay .

 

I'm sure you'll get them all sorted out..