Originally Posted by
Iraq&Roll
Edelbrock makes some decent heads for the FE engines along with intakes as you already know. If you rebuild the original heads upgrade to hardened exhaust seats.
Pick a mildish cam like the Comp 268. The rockers are a rail type from the factory. You can get adjustable versions for not too much.
Look for a truck 360 electronic distributor. Getting rid of the points and using a MSD box will wake the old engine up too.
+1 for getting rid of the points. Not sure on the actual HP gain,.. but you WILL feel the difference in the seat of your pants. The engine just runs so much smoother and the power band feels so much wider after. Every car I ever swapped to electronic ignition felt so much better after.
Be sure to check the combustion chambers if you do any head swaps. 66 390 engines could be made to run. The best 390 heads were found on the 66 - 67 Fairlane GT, 66 - 67 Comet/Cyclone GT, 67 - 69 Mustang GT. 68-69 Cougar GT, Also,.. the last year for that motor and those heads.
Best early intake was the dual 4 high rise and the 3 deuce setup. Rare and hard to find today. Next would be just the regular 4v GT intake.
390 is in the FE family. 360, 390, 428 and 427. 429 and 460 are 385 series motors and DOVE-C heads wont work on 390 motors. FE series engines used 4.63 bore spacing. 429 - 460 used 4.90 bore spacing. The heads do not interchange. The FE series were referred to as a medium block,.. the 429 - 460 were called big blocks because of the bore spacing.
Best heads were the later 428 SCJ heads found on the Mach1's, Cougar GT, and GT500 and a few others, casting ID is C8OE-6090-N. Second choice would be the later 427 heads, C6AE-6007-A . Odds are you wont want to pay the premium for any of these heads. Edelbrock makes a better SCJ aftermarket head that works on 390 engine and will cost less than any stock 'performance' head you come across.
Hurst