With a GT40 intake setup, I did not have those issues. I stayed with drivers side facing TB for other reasons besides the ones nvrstuk listed. I am using stock truck 351w fuel rails, but if I were to flip the upper around to face pass. side, I would use an Explorer fuel rail and re-do the cross over hoses on the back of the fuel rail. I have no spacers, but I do have an EGR spacer delete plate that is roughly 3/4" thick. I only used that so I had the mounting boss for the Mustang 5.0 cable bracket.