Hello ,working on a 73 Challenger was a 340 auto Ralley car ,bought it no drivetrain have a built 76 440 and a used 4spd. .trying a trail fit this weekend bought a Brewer repot bellhousing BH 513R. Which hole does the Z bar use there are two ,upper and lower ??? my car was an auto want to set it up so I can weld bracket that holds Z bar to top of frame rail ,thanks first mopar thanks Gregg