I am interested in replacing the headers with aftermarket long throw headers to get more of an older style sound. Has anyone installed a set without pulling the motor?

 

You have to raise the motor a little. I believe you can do each side seperately so the motor doesn't actually come out.

 

That is correct, the engine does not have to be removed. You can look at JBA's site, they have a complete instruction set for installing their long tube headers.

Long tube header installation instructions

 

I just installed them yesterday, went very well. Took 5 hours and that was me and my wife installing them. I also included installing the Steeda engine mounts. I lifted the car with a jack, placed normal jack stands under it and when it came time to lift the motor I took out both engine mounts and lifted the engine with a block of wood on my jack without any trouble at all.