Hi boxhead, Dimis, Craig,
Yes 10k is OK and they are quite major changes too. There are other things to consider as well.
ERA are the best guys to be doing something like that, however ERA have plenty of other 'stuff' to keep them busy.
Further, that car is on the other side of continental USA to ERA.
Side pipes would need to be replaced with undercar exhaust with cats.
Craig's comments about emissions compliance are correct. 1987 emissions requirements would need to be adhered to.
So it's not just the cost totalled, there is quite a degree of risk there too. What do you do with a car that you have a lot invested in that you find you can't register?
And that cost, while not excessive, could be better applied elsewhere....
Cheers!
Glen