I would think you would want to know what camshaft You have . It sounds like you dont know weather you have a solid or a hydraulic lifter cam. You can find the numbers on most camshafts, many have the name and grind# stamped on the end of the cam. Use Your amagination and do a little research . You can figure out what you have. Most 461 heads had 1:94 / 1:50 valves But some had 2:02 / 1:60 valves . Who knows, You may even have 461x ,which are the best . Do You have Flat top pistons ,dish or Dome piston. What piston is it ? Whats the part # ? What is the rated compression of the piston? Oh, the head , the number and build date is on the head surface under the valve cover.Now is the time for You to figure out what You have. Right this minute You have a P I G in the Poke as some southerners would say. Are we being ugly? I dont think so ! Just trying to get You to do it the right way. Good Luck!