Re: New Engine left with questions..Cam help needed
Sounds like you need more duration. 230 @.50 for a 383 is not very large. A 245-250 @.50 would be more the ticket. Also, has the existing cam been degreed? If not, it could be advanced, causing you to run out of steam at 6300. My blown big block used a hydraulic roller: 612 I & E, 256 264 @.50, and peaked at 6200 RPM, 114 degree lobe center because of the blower. It was a great street cam, and would idle at 1000 RPMS all day, even with two honkin carbs. The cam should be heads up, and the duration increased IMO. You also want to be sure that your power loss is not due to fuel or lack thereof. Not sure if you have checked the jetting on the carb, but it could also be running lean on the top end at 6300. Make sure you have an adequate fuel pump. Alot of guys rebuild the engine and make it hot, and use the same fuel system. Just a thought.