hi lee, you need a series 2 block from a turbo motor, it has oil feed and return already in but they are blanked off, so you just undue them,. also ion the front face of the block above the water pump it needs to be smooth, not a rough casting there are 2 types but most series 2 block are smooth, bernie.
thats my series 2 block. if you look in the middle at the bottom of the block you can see were i took the bung out for oil return, also the smooth area. you have too drill and tap that for the new tensioner positioning..