a std cvh build can cost alsorts, depends if u wanna go whole hog
the list is huge for a full build
the pumps, a crank grind, rings, shells, hone/bore, gaskets, bolts, clutch oil, filters, seals, guides,skim etc etc
that little lot will cost a lot of beans but its still nessicary if you wanna do it right, poss it would need more on top, or you could throw a new ring set on teh low cyl and hope for the best urself for £50

presonally i like to dump a engine with issues in the corner and fit another but that can cause more probs, my last engine done less that 100 miles b4 oil pump went and it was replacing a engine tat did teh same the week b4
but then again some ppl spunk 1500 quid into a lump and it will last 100 miles also b4 goin tits up,
its a minefield