I have been to the last 4 drag weeks and finished all four ( a couple barley limping in, but finished!). Just an opinion, but switching third members for the drive might not work out so well. By the end if the week you will be exhausted, not to mention the valuable time it would take up everyday. Most of the route is through back roads and short highway stretches that you will be running 50-55mph any way, that should not be a problem for a 4.10 with a small block. My first year I ran 4.10 with a big block, and yes there where a few times the highway gear would have been nice, but it was no big deal, (certainly not worth the effort of changing third members). By the end of the week I was not licking the amount of time I gave up just to change the slicks and frontrunners! getting in before dark was way more valuable, especially if I had problems on the road, which I have, eg. head gaskets- (always fun pulling the whole top end apart in a trailer park!) clutch- nothing like putting a clutch disc in at a motel parking lot! valve train issues galore that ate up all kinds of time. Any way good luck with the project, whatever way you go with it, Drag Week is by far the most enjoyable car related event I have ever done, I recommend it to everybody who is even remotely interested in it!