Moving the engine back

Looked at the car last night. I can move the engine back 6” with a rear sump pan and a crap load of work…. That would move the firewall to the seam line the stock floor pan. It would require moving the engine back 14’ to hop the stock steering with the current pan. Way to much work and no leg room.
My gas, break, steering, and trans mount will not be any issue. Looks like I will need a new pan and the drive shaft trimmed down.
I know it’s a huge undertaking but will 6” move rearward make any difference in 60’ times?