I purchased the extension rod for a V8 through Classic Industries, and it was way too long....ended up cutting it almost in half then re-bending the end of it to form a new eyelet for the spring to fit into. I just "trial and error'd" it till the tension was close.
1967 Firebird 400/4spd all numbers matching 1971 Camaro Pro ET Drag Car 1970 Camaro real Z-28 (needs everything) 1963 Impala 409 dual quad 4 spd 2003 Victory Vegas 2009 Pontiac G8 GT (My wife says I have a problem.....)