ATF in the cylinders, breaker bar, crank bolt, patience, back and forth, MORE PATIENCE
READ CAREFULLY BEFORE TRYING THIS TECHNIQUE
alright
tell us what you did to confirm that the lower end was seized...
if it is infact seized, then this trick may work for you
but you NEED PATIENCE with it...
first check to make sure your timing marks are correct, you want to make sure it didn't jump time and smash the valves, cause that could make the motor not turn over as well...
if you are confident that its the lower end then take out the spark plugs and fill the cylinders with ATF, yea, thats right, automatic transmission fluid...
then let it sit for a day, yea a WHOLE DAY
now you need a big ass breaker bar with a socket the size of the crank bolt...
the next step is what takes the real patience...
you slowly need to try and turn the crank, back and forth, back and forth...
when i started on a seized motor i could barely get it to move like 1 degree, and then i kept working it back and forth and i got to 2 degrees, and then 3, then 4
it takes a lot of time and patience to get the motor to fully turn over again, but the ATF should do the trick...
this was done on a saturn that was starved of oil and locked up TIGHT...
you might have to use a pipe on the breaker bar to get it to start moving
and you want to turn it until you run into resistance, then go back the other way, you DO NOT WANT TO FORCE IT... it will require force, but you need to know how much is too much
the key is SLOW AND REPETATIVE, back and forth, and if it doesn't budge after a day then give it another... this has been proven to work so trust me... best of luck