I had my Mk3's original engine rebuilt as a turbo block back in May. I got the CPS hole drilled at the same time so that I could run FRST management.

Be warned though - the NA and Turbo block castings are different. The turbo block has extra metal on the inside where the turbo oil drain hole is to "point" the oil straight down into the sump. When you get a NA block drilled the drain stub just pokes through the wall and the oil runs down the inside of the block.

I converted mine because I wanted to keep the original engine number. I also got the bargain of the century with a new set of pistons, rings and shells for £20 of ebay. Made it a no brainer really rather than buying some unknown RS turbo block that could turn out to be a pile of crap...