Good morning, Whimpy, and welcome to Stovebolt. Congrats on the GMC panel truck.
FYI- for questions and answers the best place to ask them is in the garage forums. Your current questions would be best asked in the Engine forum, or perhaps the General truck forum.
....but I will add that there are many ways to free up and old engine. Along with what you have done, buy a flywheel wrench that you can put on the flywheel and help spin the motor. They aren't expensive and you'll use it more than thank you think. you can pry on the flywheel with a big screw driver but you don't want to brake anything!!!
Some folks use 50/50 mixture of transmission fluid and diesel fuel and many other concoctions. Its a slow process but can be done with patience.
I will add that I had a 261 engine that I ended up pulling the head and "pounding" on the pistons to get it freed up but hope you don't have to do that.
Last edited by Peggy M; 09/17/2023 5:27 PM.
