Depends who you ask and what day you ask it on, seriously.
One enquiry saw me facing a hefty bill from an engineer, the next didn't, so I chose the latter option
I have a 202/Trimatic in my FE that is Regency approved, I have a HR front-end, front discs and chassis kit, but the chassis kit was more for my peace of mind than a requirement of Regency. They also approved 235 wide tyres on the rear
Regency may still have a list of guidelines booklet, head in there anyway and get an application for approval in principle or they might have the forms online. Once you have filled out the application with all the mods they send a letter back (weeks later no doubt) with either an approval, approval with conditions or a big no.
HTH