My two cents on this, having lived in Southern California, where fuel quality and traffic flow sucks while ambient temperatures can be stifling, my whole life, and having built and daily driven some not quite practical for daily driver status combinations, tune up is essential.

Run as much static initial timing as you can get away with. It absolutely makes a difference in engine temperatures. I’ve regularly had to run initial timing in excess of 20 degrees to get a strong idle and not overheat. As long as you have a clutch or a loose converter, the engine doesn’t try to diesel when you turn it off, amd you don’t have warm start issues, you’ll be good.

Beyond that, a quality, stock replacement big-block or air conditioning sized radiator with no blocked tubes, either aluminum or copper and brass (I’ve successfully used both recored factory and stock replacement Griffin or Cold Case, none of that champion brand stuff…), a factory style fan shroud, a factory air conditioning or smog era 6 or 7 blade thermostatic clutch fan, a 180 degree thermostat with one or two 1/8” diameter burp holes drilled, and a slightly underdriven (yes, underdriven) high quality (Edelbrock, Milodon, Stewart, or Flowcooler) water pump works for me. Use just enough antifreeze to prevent corrosion, water cools best. Having at least a liter sized overflow or burp tank keeps water off the pavement when the temp spikes after a hot shut down, allows the cooling system to draw it back in. The little import car section at the pick-a-part is a good source for the overflow tanks, early 90’s Geo Prizms have my favorite with a nice little bracket that allows you to pull it out and flush it.

As with all advice, your results may vary, but decades of trial and error have brought me to the above…

Just received two pairs of Cody’s billet steel caps. They look beautiful, looking forward to putting them into service at some point in the hopefully not too distant future!

Thanks Cody!

In my experience with multiple unibody based Ford cars, weld in subframe connectors that tie the torque box at the front rear leaf spring perch to the rear of the front frame rails near the toe boards absolutely make a difference in resisting chassis twist and improving vehicle stiffness.

As of today there’s one listed for sale on the other forum

https://www.fordfe.com/rare-dove-fe-427-hr-magnesium-1x4-spider-intake-t170278.html

My experience with lockers is that they like to coast a little bit, off the throttle, before making a turn, especially with a manual transmission. Coasting a little allows them to disengage fully so you don’t get the chatter that tries to shake the car/truck apart when trying to turn. I kind of like the soft ratcheting noise when making a tight part or off throttle turn. Lockers are cranky and take a little getting used to, especially with a manual transmission and in the rain, but once you learn the nuances, I love that when you jump on it it tries to go straight. I’ve used them in several daily driver type cars and trucks that got flogged regularly

Given that Mr. Jay Brown created and maintains this forum, I'd say the general consensus, and might I add decent thing to do, would be to 'send him a check'. It'll be a worthwhile investment into your library. 

PM sent

I swapped from a port matched F427 to a port matched RPM to a ported (collar removed from plenum, runners blended into plenum, runners opened up to MR port size at head and blended up into port) Streetmaster on a fairly mild 428 build a few years back. Combo was .040 428 with CJ style dished pistons, heavily ported C6AE-R heads with 2.09/1.66 valves, about 10.1 compression, mild Crower hydraulic cam with 220-228 @ .050", 112 LC, .540ish lift, Holley 780 VS carb, 1 3/4 inch primary tube headers into 2.5 inch duals, C6 auto with 2,200 rpm stall, 3.89 rear gears with a tall tire. Ran this in a 3,900lb 65 F-100 SWB truck.

With both the F427, then the RPM intake, it had gobs of power as soon as the converter stalled out, would blow the tires off pretty easy (too easy). I think the F427 and RPM were on par with each other for that build. Swapping to the Streetmaster, it lost about 1.5-inches of manifold vacuum at idle, and was noticeably softer below the converter stall, but above about 3,000 rpm, it came on hard, and according to my seat cushion, pulled much harder through the mid-range up to the shift point (about 5,500 rpm). I was able to control the tire spin better too, so I felt it was a win on my combo, for what I wanted. Cruise rpm with this combo was about 3,000 rpm at 70 mph, and I noticed no change in driveability or economy in this range. I did have to diddle with the power valves, jets, secondary spring and timing a bit between the two intakes. The Streetmaster worked best for me with a 4 hole spacer on top of an open spacer, where I ran the RPM with just a 4 hole spacer.

For my current 428 build, same truck, with more compression, Edelbrock heads, huge solid lifter cam, 3,000 stall converter and wide ratio gear set in the C6, I kept the Streetmaster and am pleased with it.

For your combo, given that you have more weight over the rear tires than my truck and likely traction will be improved, I'd probably go with the F427, for as others have said, it will look 'right' in that engine bay, and will be in the sweet spot for your driving range.

Brett