the best thing to do is give it a good service with every thing oil plugs the works forget about the bearings and pistons. if your wanting that much your cheapest and best way is buy an engine running or not can get them cheap then build it in your spear time or in a day for less the £500 for a band new block however original pistons are hard to get infact i think i got the last set in country and the engine will be good for upto 200 bhp with all standerd inturnals