ECU's have changed substantially since the 80's. Hell just in the last 5 they've come a LONG ways.
If your curious, look at tuning options for any EEC-V SVT and what they run into for problems. All of them use the same main board, programming and parts change from 4 to 8 (injector drivers and such). Pinouts are identical though.
Unless he's worked on them firsthand, I'd write his claims off as smoke up your arse.
FWIW, SCT was started by a former Ford engineer and is still owned/operated by him. Even he's said that the new tech is getting tricky.
Also, EECTuning is a decent site for the grassroots tuning of Fords. I haven't seen much in the way of SVT talk though, least not working.
Don't "think outside the box".
There is no box.
Do it correct, or do it twice.