I have a 1967 283 2 bolt with mid 60's power pack heads, what can I do within reason to increase hp? It has a 600 cfm edelbrock carb and performer intake. Also what spark plugs would be recommended? ( heat range? Gap?). Thanks also it has HEI ignition. Sent from my iPhone using The H.A.M.B. mobile app
A cam would be a great start, along with good exhaust manifolds/headers. I am building the same engine. I'm installing a copy of the L-79 cam (1966-67 327/350hp). Every one that I have heard sounds healthy and has been said to really liven a 283 up.
L-79 cam, AC 44's .035" to start. If the plugs show rich just open the gap until they don't. If you lean the carb you may not be able to increase the gap. Fuel is power, if you can ignite it you make more. With flattop pistons and shim gasket you are at 9.25-1 comp ratio. With a Felpro style blue gasket its lower maybe under 9.1. Gaskets make a bigger difference than you think and there are web site formulas to do it. I use United Machine for my calculations. My guess with the added cam and the combo you show right at 270 hp....without 230-40.