460 or 463
Something of a dilemma between the 2 vehicles you have talked about. Diesel, as everyone has pointed out, is by far the best choice.
Having said that the 463, if it’s the one you have spoken about on GWOA, has some pretty unheard of faults for a G of that vintage, broken axle, transfer box, gearbox etc. Nothing that can’t be fixed but major money and suggests a pile of other stuff hidden and waiting to bite you. They are not that much slower than the 280, so your comment about it being really slow suggests other issues with the engine as well.
The 280 has an absolutely brilliant fuel injection system, K Jetronic. But only when it’s in good condition and well set up. Requires some relatively specialist knowledge, tools and experience to fault find. First bit of crap to get past the filters will destroy the fuel distributor. But then I guess you could say that for most systems, including diesel. I have seen them trashed in the UK though due to this.
On balance the 463 sounds a liability so it’s the 280 but far from ideal. Good 460’s are rare.
Maybe I’d suggest a diesel engine transplant in to the 460 but IMHO that’s not as simple as it may first appear and just adds another failure point.