V8 swap- parts list? 66 signet, 225/904 floor shift

Ok I'm gettin the hang of this! So; another related question, will 67-72 upper control arms (for SBP disc) work on my 66?

Yep. All the A-body control arms, upper and lower, will interchange. The later ('73 and up) disc uppers take a larger ball joint, but all the others should be the same smaller one.

Also, how about torsion bar interchangeability? Can I use the 340 bars from a 67 barracuda?

Also yes. All A-body torsion bars interchange. Make sure to keep the even-part-numbered bar on the right side and the odd-numbered on the left.