Speedometer cable location '69 Valiant...

I'm installing a new speedometer cable on my '69 valiant. Small block. Have the speedometer end connected to the dash and ready to connect the transmission end to the transmission. Second time around putting in a new cable as the last time the speedometer was jumping around and sending high readings (85mph when doing around 20mph). Checked and wasn't kinked. Used powder graphite inside the cable housing this time to lube. Hope that wasn't a mistake.
Speedometer/odometer have been rebuilt. Anyone know the cable's best routing path to the transmission from the firewall? Thanks in advance...