Plenty of good advice already here. I think the main thing to stress is to do your best to "get to know" the power of your car (a little at a time!). Your 418 will be a lot different than the 351 you drove at Dynamic (do they still use the white car?). What cam did you opt for in Eric's engine? He's one of the BEST, and you will enjoy the car for a long time (as long as you're careful!). Get some "Fix-a-flat" for the glove box, and keep a cell phone on you. A car cover is a must.........make sure it's clean before you cover it though....and don't melt the cover on the pipes. If it's not too late, I would get the battery kill switch and the radiator screen. Floor mats are a must too (IMO).
Other than that, just BE CAREFUL. Go to an empty parking lot and get used to what you have. 500HP + 90 inch wheelbase = TROUBLE if you aren't careful. ........It can also = FUN once you get to know it better!