700-R4 tail housing trouble

[bigblock69]

I posted yesterday and I got some of my questions answered; however, I have some left unanswered. I am putting a 454 in my 68 C-10. I am using a 700-R4 and an Early Classic transmission cross member. Problem is this. The tail housing is hitting on the cross member. No problems right, just use a spacer. Well I contacted Early Classic and asked if this problem has ever occurred before and there answer is “never heard of it happening before” why are hundreds of Early Classic customers having an outcome other than mine? I am using the correct 67-71 big block engine mount towers and the correct big block engine mounts. The engine and transmission were only sitting/not bolted down when I noticed the tail housing hitting. Could this have something to do with it? I have since pulled both eng and trans out to collect my thought on this. Any help would be greatly appreciated.