mack505

This is probably another n00b question, but here goes. I have a 1950 Type 505A with a 510ci Thermodyne. After about a year and a half in storage, it's down on power, especially climbing hills. I've changed the fuel, and I figure the next steps are fuel filter and tuneup. I have the parts, but I don't have any specs on plug gap, point gap, timing, etc. I've done a quick search but don't find any. Does anyone have a source for this information? I know people tune up their trucks all the time. . .