Tower Hobbies. Look under parts for the FI version of the 1.60. I agree with Eric. Drilling the cracnkcase is a lot easier than messing with the backplate. If you don't get the threads absolutely flush on the backplate, the con rod WILL hit it. I just converted a friends 1.60 who had this exact issue.

Here's how you drill without getting junk in the crankcase:

Take the backplate off.
Stuff a paper towel soaked with oil into the crankcase, in the area of where the drill will come thru.
Use a 1/16" bit in a drill. Turn the engine so that the crankshaft is vertical, and drill the hole from the bottom so the shavings fall out.
Keep the engine vertical, and keeping the paper towel stuff against the new hole, spray the threads out from the bottom with some automotive brake cleaner.
Turn the engine upright and carefully remove the towel. Most of the shavings will have fallen out the bottom, and the oil on the towel collects the rest.

I've used the Perry pumps for two years without an issue. Had zero luck with the regulators.

Jon Lowe