The +8 is fitted with a Salisbury Axle, the Roadster with a BTR.
The hubs will need careful lapping onto the driveshafts to ensure the tapers mate, but the hubs are interchangeable.
I wouldnt advise redrilling the drum. You can just about overlap the stud patterns, but its not nice...
The 5 stud drums aren't expensive enough to risk any potential issues
You might find that the Roadster axle is a wider track than the +8 though, which leads to issues with wheel arches and the handbrake rods, you will also need to fabricate a "xmas tree" and weld it to the BTR axle for the handbrake rod pivots
