76 TA header problems
It depends on the headers. I have taken out 400's and 455's with 3-tube headers on them without removing the headers. It was tight and the headers did touch here and there.
If you are concerned about scratching your headers up because they have a fancy coating on them, don't attempt it. If you don't care then go for it, but have a buddy with you to help "massage" it out of there.
Another option is to hoist the engine up a bit and then work at the headers bolts while there is more room. BE CAREFUL, I don't trust hydraulic hoists much. If it comes down on you, you won't be happy.
If you have 4 tube headers forget it, it is not going to happen.
Just buy a cheap 7/16 inch wrench cut the open end side down to a little stub and get at those bolts.


