1958 ish 235 ,tearing this engine down to see if it is good to rebuild .It was stuck and has sat with oil for a few years in the garage but has not moved so I took the pan off and head and only found a bent push rod and stuck valve .I got the pistons out a few days ago and they look like origional gm pistons the rod bearings look okay as well as the crank so far .I tried to pull the harmonic balancer off and it won’t move .tried a few times using puller and impact ,then using puller and breaker bar ,I used a little heat with a heat gun to warm up the area ,no go .The puller even bent slightly.Any suggestions,
