29 MPG, holy hell! Back when my Integra actually ran properly that's about what I got in it cruising around for work. If I can get the Corvette to do that, I'd be thrilled!

As for the coil selection, I was going for one I found a deal for. I still haven't had the budget to jump on them yet (as expected; the not-an-LT1 race car got priority since we have a race coming up in the middle of October), but they're too good a deal to pass up. According to the ad they're 12658183 as you mention above, but...well, we'll see about that. I won't trust it until I have them in my hands. That being said, if they really are that part number, then I'll be totally stoked. If all goes well I'll be able to order a set in one week!

Of course, that would mean the race car has no more surprise maintenance. I'll let you know.