"What's a flexplate?"

The flexplate bolts to the crankshaft and the converter bolts to the flexplate. It has a ring gear around the circumference of it that the starter pinion engages into to start the motor.

" How will the inspector determine whether it's capable of going faster?"

If you show up at the drag strip with the list of equipment you've shown at the top of this thread, he won't have to be a mental giant to know that the truck is capable of going faster than 12's.

" what is the procedure for getting chassis certification "

Call Jim Collins, the NHRA Southeast Division Tech Director at 757-686-2222 any Tuesday or Thursday evening, 8:00 to 10:00 PM. He can tell you when and where they'll be doing chassis certs or he can arrange for a chassis cert inspector to come to your house and inspect the cage.

" I dont' think mine will go that quick but I plan on driving it on the street."

It might if you select the proper pulleys and you're able to make the rear hook up.

Try to get all the receipts from the builder where he bought all the goodies. You'll need purchase dates to verify SFI dating if the parts aren't tagged and dated.