A 4x2x2 would be better but that tank could definitely work for a bull snake and I think you'll be ok with a carpet in there too. My 6.5 ft bull is in an AP T8 4x2x1 and she has plenty of room. My young carpets are in a split T8 for now but will upgrade to a 4x2x2 or 4x2x3 as they grow.