the ulp/super cylinder heads are the same, but pistons are different- huge dish on ulp pistons. also, if you're thinking about doing an efi conversion, get the ulp xf setup- it runs a knock sensor on the front rh head bolt. This allows them to run more advance and so make more power- about 10-15kw from memory. in regards to the advance, there is no advance mechanism in the distributor, it's all cotrolled by the computer,