C8AE-H heads are great. The 428PI engines got them from 1968-70 and are the engine that got me interested in the FE. If the original valves have become recessed over the years because of valve jobs or heavy trailer towing, then you'll want to install CJ sized valves. Otherwise, stock sized valves are fine for streetable performance.

To wake up your engine, you'll first want CJ exhaust manifolds (gives the stock appearance but eliminates those horrid 390Fairlane/Mustang exhaust manifolds). They are available as reproductions, but are not cheap. FPA headers for the 390 would also fit well, would perform even better, but would detract from a stock looking engine bay but are recommended for max performance. Hooker SuperComps don't fit those heads at all.

Next, you'll want an Edelbrock RPM intake (not for shaker scoop cars because of the carb pad position), though the carb will end up sitting maybe a half inch higher on the engine, so you'll want to check to see you can clear the hood with the stock aircleaner.

Lastly, you'll want a cam kit. Nothing fancy will be needed to wake the car up. I say "cam kit" because the lifters absolutely must be replaced with a new cam or disaster is guaranteed. With a new cam, you'll require new valve springs, new spring retainers, valve locks, valves (the locking grooves are in the wrong position), and rocker end-support pedestals (offering shaft support at the end positions - an easy bolt on and very important with a non-stock cam). For greatest street reliability, keep the lift below .550" to allow the greatest chance of compatibility with your non-adjustabl rockers.

Since octane is a concern with you, you can drop compression inexpensively using 390-2V automobile pistons of the 1966-70 era (not 1971 era cars and not pickup truck 390 pistons!). The engine will not need a rebalance, though it might be nice to weigh an old piston/pin combo and compare it to a new piston/pin combo just to be sure they're identical (withing a few grams). Note that factory pistons apparently use the pin when balancing, so it must be kept with the original piston and included when weighing, as different pins weigh differently. Otherwise, Silvolite and others offer mild performance pistons for the 390, and most of the non-racing ones tend to try to match the stock piston weight.

The stock distributor is great, but you'll want to dump the points and install a basic Pertronix ignition conversion. The cheapest model is best for street applications. The distributor will likely deserve a recurving to assure you have a centrifugal advance curve which applies to modern gas and cams. There are shops that know exactly what to do. I'd keep the stock coil, as it's great for street performance engines that are not excessively revved and the stock coil is calibrated for the ballast wire that runs from your ignition to assure optimal energy transfer. Oversizing the coil can cause complications if you are not prepared for them.

Since you are rebuilding, you will likely replace the bearings. The rod bearings will likely have taken on an egg-shape, based on the notion that the forged steel rods tend to elongate as the years pass. While you can replace the main bearings without bore issues, you will likely need to refurbish the big end of the rods (resize is the term), in order to make them perfectly round again. If thay are obround by more than .0005" (they likely are), you will have reliability issues if you simply replace the bearings with new ones, since circular bearings are being installed into egg-shaped rods. Failure is common if the rod is not resized. While resizing, you might as well install all new rodbolts. Stock rodbolts are nice and strong, but thay are allowed to have somewhat severe flaws in them, from a racing perspective. Rather than magnafluxing the stock rods to assure they all have reasonable flaw features, it's typically best to simply install ARP bolts. Adding arp bolts also REQUIRE resizing the rod, since they have a different clamping force than stock bolts (different torque) and thus the rods big-end takes on a deformation away from round. With new bearings and new ARP rodbolts, resizing the rod is a double-value. FE 390 rods are fantastic performance rods whwen equipped with magnafluxed stock bolts or ARP bolts with a resize.

All FE cast iron cranks are made from the same pearlitic nodular alloy, and all are worthy of very high performance applications. Yup, that means the 390, 406, and 427 cranks are all about the same in strength. They're probably stronger than any 410/428 crank, too, since the "journal overlap" is more robust in the 390.

The stock oil pump is a great idea, as HV or HP or HVHP pumps cause a whole myriad of complications if you are not prepared for them. A stock oil pump can work with a stock oil pan, but a performance pump really requires an aftermarket oil pan with extra capacity. Your engine has done great with a stock pump, and oils have improved, so I'd stick with a completely stock oiling system and forget the hype about oiling mods. If you upgrade the pump, do some serious forum research, or else expect engine problems. I'd add a windage tray ($40 or so new) and would advise overfilling the oil pan by one quart and keeping it to that level. Damage can result if you have a fast FE and a stock pan - things are worsened by a performance oil pump with a stock pan. Zero damage will result with an "extra" quart (running six instead of 5) and a windage tray. If you make your car really fast, or if you add a non-stock oil pump, you'll absolutely need a baffled high-capacity oil pan for longevity.

Just some ideas to get you started,
Shoe.