Help with BBC in a 67 C-10

[kell490]

I have been working on this for years just now getting to the point where I can mount the engine. I just assumed pickup would have enough room I'm having issues with the tall valve covers hitting firewall. 20/20 hindsight I would have gone with a 68. I'm also using those CPP engine mounts maybe that's the problem need stock engine mounts so it sits lower. I bought the truck had a 350 SBC in it. I can look into smaller valve covers but I see pictures up here with BBC tall covers any ideas would help I can get stock engine mounts ditch the CPP mounts.