I wouldn't recommend the Doug's . I have them on my Ranchero and it took lots of mods to have them fit still can't do a hard left turn, pitman arm hits tube. Also they don't line up with the "humps " at trans crossmember so you hear some knocks.
 Not sure how other manufacturers fit.
 Only bonus I had with them was price as Amazon delivered them for like $350. Was a nice price difference over regular price. Had them around for about 6 months before installing.

Here's some pics of install. Engine and trans.

11:1, that cam, the valves in control, and running closer to 12.5:1, I think you will see significant gains in power and the peak RPM will shift higher, as Brent pointed out, not TFS numbers, but I bet that engine will pull to 6000 and make 480-490-ish.  Yes, 260 cfm heads fight back, but I think there is more in there. 

Also, with all respect to your friend...if you really are at 125 closed, I recommend you jump back in, I do not think he is right.  A Morel is pretty tough, but I have seen other brands break link bars with higher seat pressures than you see.  I thought I saved pictures of a 428 PI with 130/320, can't find them but I will look

ON EDIT:  It wasn't a PI that had the failed lifter bars it was an all iron CJ, and here is what I found under the intake.  Seat pressure was around 130, but all over the map, and open was low but not horrible.  I don't love Comp lifters, the bar is weaker, but if the valves were in control this wouldn't have happened

BTW, just as a repeat after playing with some numbers, that cam is stout at 82 degrees of overlap, generally considered a whole lot...

I'd do the springs, 175/420-ish notch the divider and a little blending on the roof of the plenum and lower plane short turn if it's sharp, put the cam at 108 ICL, might like a cooler plug depending where you are, lean it up, give it some timing and let her eat.   Would be nice to see another round of dyno as I spend your time and money

 That's a bit of pain in those pics.
 Cam my buddy wanted about 20* more duration, believe it or not. When I called Bullet and talked with them turned down first cam forget the numbers at this point . Got these numbers and the 104 ICL and felt that would do pretty well. Build the cylinder pressure. Sounded pretty good on the dyno not wild in my book, but nice. Think the overlap is in a "fun" area.
Can I pass it off as a thumper to the bowtie boys?
 Had thought about notching divider but had to rein myself in. Street car not race. Actually more show car that's driven . I know boring !
 Plugs are Autolite 3923 and may switch to a colder plug yet. I'm east coast around Philthadelphia, Pa moved here around 2015. So close to sea level.
 Timing was set at 14 initial with a total of 36. Don't know I can put much more to it on 93 octane.
Jet will happen once in car and corked up. See how it reacts with the 2-1/2" pipes and flowmasters.
 I can spend all kinds of fantasy money !!

Performance Summary:
      Cubic Inches:   462            Dyno brand: Superflow
      Power Adder: N/A              Where dynoed: CTS Ridgely, MD
      Peak Horsepower: 447 @ 5495
      Peak Torque: 540 @ 3180

Horsepower and Torque Curves:


Engine Specifications:
   Block brand, material, finished bore size, other notes: C scratch  4.160
     
   Crankshaft brand, cast or forged, stroke, journal size: Cast, Eagle, 4.25"
     
   Connecting Rods brand, material, center to center distance, end sizes, bolts: Eagle I beam 6.700"

   Piston brand, material (caster, hypereutectic or forged), dish/dome volume, static CR: Mahle, Forged, -7 cc flat , 11.1

   Main Bearings, Rod Bearings, Cam Bearings brand and size: MS-685P, CB-743P

   Piston rings brand, size, other notes: Mahle, 1mm,1mm, 2mm

   Oil Pump, pickup, and drive: Stock, Milodon 18370, HD drive

   Oil pan, windage tray, oil filter adapter: Milodon 31130

   Camshaft brand, type (hyd/solid, flat tappet or roller), lift and duration (adv and @.050")  Bullet, Hyd. Roller, part # 505000, 293/303 Adv, 242/248 @.050 .605/.616, 108* c/l,  104 ICL

   Lifters brand, type: Morrel, hyd roller

   Timing chain and timing cover: Cloyes true roller, factory cover

   Cylinder heads brand, material, port and chamber information: Ed knockoff, Aluminum

   Cylinder head flow in cfm at inches of lift (28" H2O pressure drop):
      Intake               Exhaust
      .100   63             .100   52
      .200   144            .200  96 Turbulant
      .300   173            .300  135
      .400   227           .400   174
      .500   255            .500  195
      .600   267            .600  207
      .700   277            .700  N/A
      .800   N/A            .800  N/A

   Flow bench used, location:  Superflow, CTS Ridgely,Md

   Intake valve brand, head size, stem size:  Manley cut down to 2.190",  11/32", +.250" tip

   Exhaust valve brand, head size, stem size:  Manley 1.900", 11/32", + .250" tip
   
   Valve springs brand, part number, specs:   Manley, 22406, 1.875" inst. @ 125lbs.

   Retainers and locks brand, part number, specs: Manley, 23636-16, Manley 13194-16

   Rocker arm brand, type (adjustable or non-adj), material, ratio:  Harland, Adj. , AL, 1.76

   Rocker shafts and stands, brand, material: Harland

   Pushrods brand, type, length: Smith Bros. 8.400. ball&cup

   Valve covers, brand, type: Factory chrome

   Distributor brand, advance curve information:  MSD

   Harmonic balancer brand: ATI

   Water pump brand, type (mechanical or electric): Mr Gasket, Mech.

   Intake manifold brand, material, porting information: RPM Knockoff

   Carburetor(s) brand, type :  Holley Service replacement U carb

   Exhaust manifolds or headers brand, type:  Dougs Headers

 Well the plot has thickened yet again ! Had the engine all together and up on the dyno set timing and just checking things over pulled dipstick and found "frothy" oil, was running 6 qts in 7qt pan as a test. Added extra qt to no avail.
 So here is what has happened over many weekends. Ended up finding that pump was pushing oil out at input shaft and "froth" there.
Reworked an old pump and put all back together, oil pressure was down about 20 psi running on drill which made us happier was about 70 psi before on drill. My buddy was running it later in the week as he tries not to offend neighbors with dyno runs after a certain time in evenings. Checked the oil and found water in oil checked her over and came up with manifold leak in one corner. So machined manifold to set more uniform and figured it was fixed. I had went down and spent a day cleaning the gunk out of everything and re assembling. Again he had it running later in week and found water in oil. So took her off the dyno as he had another engine coming in for testing. Made some block off plates for water jacket and found the real culprit a crack in valley above a couple lifter bores. Hairline crack but I decided we aren't attempting any repairs on that block.
 So yesterday went down and disassembled that engine inspecting for anything that could have been damaged, no issues thankfully.
 Loaded my original 428 block up and gauged the bores to see where we were with them. Ordered new pistons to work with the stroker kit for these bores. Once they arrive can finish machine this block and get it all back together.
 It's been an interesting time with all of this.

I haven't used this link in a little while but it has some calculators for getting your numbers. Takes a little bit to get used to it.
Hope it helps.

https://www.gofastmath.com/Horsepower-Calculators/Horsepower-Calculator

 Well the plot thickens when we started checking flow of the heads. Not good figured they would flow a little more than they do, what really threw us a curve when we "wet" pattern the heads it shows the fuel just rams straight into the bowl wall and on the wrong side of valve.
 SO this will take quite a bit of port massaging ! Guess there goes the feeling in the hands back to all tingly again. The ports flow "wet" about like the bad ones on a BBC where 4 ports need lots of help. Just on the FE all intake ports need the help.