I just replaced the master, wheel cylinders, and 6' of line, but I am not able to get a firm pedal after bleeding. I think it's the booster, but I'm not sure It's a 1991 toyota camry 4cyl NON ABS

Did you replace the front calipers and the rear drum cylinders? If you didn't replace the calipers, you may have a seized piston. If you replaced both the fronts and backs plus the master, you may as well replace the booster and that way you will have covered all the bases. Sometimes it's easier to bring it to a shop and have them pressure fill the lines. That will solve the "air" in the lines mystery.

The calipers are good, everything in the rear was replaced.... I'm guessing the only thing left to do is the booster.... I'm not sure if that will work, that's why I was asking... It just seems like something isn't right... you know what I mean?

I recently went through the same thing with my kids VW. Replaced everything and it would not build good pressure. Come to find out, it had sprung another leak after I had replaced most of the rotted lines. If you're doing it on dirt or grass, you may be missing the leak. If you are doing it on cement and there are no leaks, try the booster. Post back if no luck after booster replacement. Good luck!