[68 P.O.S.]

Nice looking truck, I like it. I can answer a couple of your questions.

1) I believe so as well, need a pic of SPID tho.
2) Your steering wheel is from a 67-68; 69-72 have a different wheel.
3) Not sure, I don't remember if houndstooth came on these trucks. The Highlander package did. Actually, it's more plaid.
4) Yes, I believe that to be correct
5) Ehh, 3k rpm is nothing to these old engines. The easiest overdrive may be swapping in a TH200-4R if you want overdrive vs a gear swap. They're essentially the same length as a TH350, so you won't have to touch the driveshaft.