Big Block Hitting Firewall Issues

[ecgate]

I went to set my cab today on my 67 and it is hitting the valve covers on the firewall. My engine is sitting 2 inches too far back. Im running an electric fan and so I had to move the engine to the rear mounting holes on the frame for the engine mounts in order to have clearance for my electric fan setup. I don't want to get rid of the electric fan nor do I want to change my long water pump to a short water pump and move the engine forward because then I would need to get a new driveshaft also. I don't feel like paying for everything twice. So has anybody cut there firewall to make more clearance for the engine to fit. It looks as if It would be the cheapest and easiest fix. I just don't want to cut up my firewall if Im overlooking a simple fix. Any ideas or info on my situation would be greatly appreciated.