Gents BEWARE of another issue with this conversion - If your engine came from Lyc as a solid crank, fixed pitch engine, there can be another oil relief passage located in the center of the "nose" bearing in the left case half that vents oil back to the crankcase. This port must be tapped and fitted with a 1/8" pipe plug, if not, your engine will not hold oil pressure in the crank center galley and your C/S prop will not cycle!!
There is no mention of this in the Lyc literature (they do not sell engines intended for conversion). I thought there was an ECI technical bulletin (pdf on their website) that covers this conversion "fix", but I now can't find it. I will look tonight at the hangar and see if I can find my hard copy.....
Aha, did not find the original bulletin I used back then, but I found this bulletin that references the same issue -
www.aero/pdf/04-4.pdf
This is not commonly known even among A&P's. The hollow crank plug issue is well known and documented - the Lyc hollow cranks are sold for either F/P or C/S applications so the proper set up is documented by Lyc. But the engine cases are certified for either one or the other, and Lyc does not recognize a conversion between F/P or C/S for the engine cases so they do not document the case conversion. ECI does use the same cases for either application, therefore their literature does document the proper set up of cases for either application and therefore, the proper configuration of this oil drain passage.
Don't know how you would know if this passage is open in your case once it is assembled, except by a pressure test (or maybe by the model number/serial number??). The only way to install the plug in the left case is with the cases split.
I know a very good A&P in in my area (western PA) that can split a case, do the passage drain plug, and reassemble your engine in a day and 1/2 for $35.00 per hour plus the price of a gasket kit. Hope it does not come to that for you. Good luck.