http://cgi.ebay.com/1965-70-Starfire...170083544411re
Take the rear cover off, look for stamped #'s on the ring gear, something like XX/XX. Divide smaller(pinion gear) into larger number(ring gear) probably 2:73 or 2:93 or if u r lucky 3:08. Here s the "new" reproduced driver's-side exhaust manifold you need to put true dual exhaust, one the dr's side/ one on the pass'-side. You will need the modify the transmission rod, instead of straight u put a half circle in it. Here is the link, Hmmm posted first, go figure. Later, Ken