I just put in a chineesium delco with a Toyota drive gear installed to replace my delco that was in use since 1980.
I pulled the plugs and used the starter to whirl it over. No oil pressure! I pulled the dizzy several times and some how lost the timing. The sealing oring on the dizzy was a really fat thick thing - so I put the skinny one off off the old dizzy on the new one. Set the engine at TDC#1 on compression, set the dizzy pointing at #4 and the oil pump slot more or less in line. Put the dizzy in and pressed down, using a remote starter switch whirled the engine over. I felt the tab drop into the slot. Tightened the clamp - used the key and the oil pressure came right up -YEA. Put in the plugs and it ran - spark off by 1 tooth as indicated by the timing light. Watched rotator shaft as I pulled it out just enough to disengage the cam (it moves due to curved teeth) turned it that much and pushed it back down. Bumped starter with remote switch while pushing down on the dizzy - again felt the tab fall into slot. Tightened the clamp, started it up then set the timing again. Ran like champ with oil pressure. After a couple hundred miles the chineesium points bent out of proper alignment so I put my old Delco points/condenser in - ran much better. I need to check today to see how they are doing.