You guys got me scared of tti headers!

I was planning on pulling the trigger on the headers tomorrow and figured I would do a in depth search on this great forum. Now I am second guessing myself.

The car is a 73 swinger with a small block and power steering. I have been reading threads on guys with Schumacher /6 to small block conversion mounts having problems. This would not be a big deal if I had the biscuit style mounts but I have the spool mounts. I can not shim the motor and I do not want the head ache of wrestling with the engine and headers when I am installing the my rebuilt motor.

Would the shortys be a better option or am I freaking out over nothing. And yes I will be taking the measurements for the engine location but if it is not correct am I just screwed?