just installed a 350 trans on my 72 chevelle and put the car back on the ground and park seems to work but all other gears the car only rolls forward even in neutral wont roll backwards and no i didnt try this with the car running im still building the car and doesnt run yet, the trans i got from my father and he got it from someone online and the guy said it was all rebuilt and it looks that way to from what i see, also i didnt put any fluid in it yet either so the trans has been sitting for at least 3yrs with no fluid, a few people told me to put fluid in it first and see what happens, but i would of thought it would at least roll backwards in neutral fluid or not. i also checked shifting linkage and brakes and rear end and nothings wrong there, if anyone has any thoughts please help thanks