[SilverMk2]

I would go with a header. If your intake pipe is cracking and falling apart I'd do the intake pipe.

 

[SilverMk2]

You'll get much more bang for the buck with the header. Intake if your lucky is 2-4 hp while the header will probably be in the 10+ range. To tell you the truth I can't even tell a difference with the factory piping in place. If you do a header make sure to wrap the pipe, since the header can put out more than enough heat to melt the stock stuff. This is also a good idea on the aluminum pipes as well. The Al pipe can get hot enough to burn your hand real good after a moderate drive (even on the factory manifold). Also if you just have muffler on the stock exhaust, you should consider going to larger piping before the header. Another thing you might consider having an '82 would be to upgrade to the later EFI setups. If you have u-pull-it yards near you this might be a fairly reasonable idea. This should be worth a few ponies as well. HTH