My 59 Impala currently is a 348 / 4-speed car. I am wanting to change it over to the Tremec 5-speed. Has anyone on this site done this conversion and what modifications were necessary other than the drive shaft? I want to keep the same location where the shifter is now and will be using the skinny shifter handle as well. Did you run into room issues in the tunnel area? Thanks in advance for any help.