Many years ago there was a guy on the Yahoo Group who was contemplating a Rover V8 along the lines of the GKN 47D.
He was looking to bolt Lotus 907 heads to it.
Apparently, the Vauxhall 2 litre engine is essentially half a Rover V8 and as such, shared bore spacing etc. Given the Lotus 907 head was originally developed on a Vauxhall block, it sounded plausible.
Also interesting to note is the Lotus 907 head is symmetrical as pertains to the head bolts. The 907 cam trays are also symmetrical which, if all this is true, would mean one could arrange two 907 heads and four 907 cam trays on a Rover V8 block and have the ports and pulleys in the right places by default.
Of course, there'd be some engineering needed for the cam drives etc. but a lightish 32 valve V8 might be pretty cool.