Took a dump and my arse bled ---------- Rover V8 dilemma

[Des]

Is there an RV8 Doctor in the house?

I've had a block kicking around for a year, and I really have to pull my finger out and swap it with the knackered one in my car, the thing doesn't have the usual engine number, so will be a factory replacement, quite common as the later ones were made from the slag scraped from monkey metal mixed with nob cheese. This is the handstamped number, wagwan with that?

 

 

It appears it's an 'intermediate' block, so I don't know whether to call it a 3.9 or a 4.0, the casting looks like the later block with provision for crossbolting, but not drilled / machined, and has the older crank smaller mains dimensionage, annoying as I have a longer stroke crank but it's got big mains. Up top it lacks provision for the outer rows of headbolts. I've pondered having the block machined for the bigger crank, but wonder if it's worth pissing around with something that may well turn out to be yet another hardcore K-seal junkie, also, would I be an idiot, (albeit a devilishly handsome idiot) to attempt to drill and tap for the missing headbolts?