Intakes- About that Firewall to Engine Clearance Issue

So - as I mentioned earlier, the firewall is REALLY close to the engine.  So much so- that the original Mark VIII intake with throttle body at the rear, sits two to three inches behind the cylinder heads.

This means to use it, I need to mod the mounts to move the engine forward.  Or mod the firewall..which I'm already doing - but afraid to what extent it will impact my HVAC needs in the car... or try to find another intake that would work.

So - I landed here:

Casey Likey.