My friend Butch (aka "Alaskan", RIP Butch) knew Gale Banks. Butch said the 460 Ford was one of those engines that really benefitted from Headers. He also always spelled Banks "Bank$" because of the cost.
I haven't modded our 2-valve V10/4R100 combination, but from what I feel driving it and what I read on Forums, better control of the transmission's shift strategy would be the biggest plus.
Addressing the OP: I've driven the TorqShift 5R110 and it does NOT have the strategy problems our 4R100 does. The TorqShift is already smart as a trick pony. Drove it in two-valve E450 and three-valve F350. Wonderful in both cases.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB