Ive heard of some people using transmission fluid.. Not sure if its better than marvel.. Maybe someone will chime in on that.. I used marvel oil in mine. poured it in each cylinder then put a quart in the valve cover. Let it sit for a couple of days and pop the clutch a few times and it freed it up.. Been sitting 18 years.. It did take a few tries to get to unlock though.. Maybe let it sit a while longer and try it again


Daniel

1953 Chevrolet 3800 Stepside