You should be able to get a reasonably good running V8 for £200, so no, definitely NOT a bargain.
Big-Bore motors were fetching a premium a while back, but with so many P38's succoming to the scrappers, not any more.
And as a rebuild 'project' you are looking at the thick end of a grand to do a complete tear down and rebuild, excluding any major bits like crank, rods or pistons that are needed, and if seized, probably are.
As for the work, big bore motors aren't much more vexing than the 3.5's or 3.9's, differences are mainly in the GEMS engine management, which can be a bit more frought to sort if you choose to use it, but you can oblivigate that by going Mega-Squirt, or using small-bore timing cover, distributor and earlier EFi or even carbs.
If you fancy the project, I reckon rebuilding a V8 isn't any more demanding than an old A-series; its all laid out bery neatly in there and in some ways is easier to get to grips with; you just have twice the number of bits to keep in order and put back in place!
Oh, and be a bit more critical in using teh torque wrench, the block and heads being softer aluminium.
But it is a time consuming and expensive task.
Took me ten weeks working around other commitments to completelty tear and rebuild a 3.5 carb mill, a coupe of years ago; that didn't need any major bits, though did get all new valve train from the timing chain, through cam and push-rods to the rockers; and the bills including crank grind, rebore, heads skim, valve grind, bearings, seals and 'bits' to dress it out totalled I think £800 worth.
VERY sweet when finished though; ran really crisp, and made loads of power compared to before, and with that warm feeling of being hand-built, with a full compliment of life and reliability in it.
Nice project to take on, but not a particularly ecconomical one, and one I wouldn't start with an over-priced knackered block.
At a guess, I'd presume that the motor needed a few major bits in it, that would push budget, I'd also presume that it needed re-liniering, rather than just reboring, and that if doing that, you get it top-hatted, which immedietly gives you a £400 bill, and basically means that the block you are starting with is worth the 'surcharge' on an exchance top-hat linered block, less the effort to strip it down to exchangeable condition.
From memory, surgcarges vary from anything between £75 and £250 depending on who you go to; but practically what you are looking at is a scrap V8 'lump' worth its dead weight of about £50..........
Bottom line is, people give away, old V8 motors, and if you are going to get one re-linered, doesn't really matter what capacity it is, you can shrink in any of the big bore liners into any of the block castings, and what bits might be in it, if you have to tear and rebuild, are pretty inconsequential; IF you are reboring or going over-sized, you wont be keeping many of them any way!
short answer, about as far from being a bargain as Mecca is from being Jerusalem!
