Not everybody needs (or Wants) a 250+ @.050 Cam , and high RPM in 4WD vehicles with Heavy Drivetrains usually just break stuff up there.
I built lots of 460+ inch Torque motors (Buicks/Pontiac and Oldsmobiles) for friends with broomstick cams that would snap your neck from a 30-mph roll, which is just what you want in a Ramcharger. My buddy has a mid 70's Ramcharger with a stock 440, 2000-4500 is where you want the power, 100% You don't want to be going 100 mph + at 6000RPM in something with that much rolling inertia anyway.
And make no mistake the Indy 440 2D intake will support close to 700 HP even unported, 100%. So I doubt it's any restriction at all, but what might help is a bit more lift like 1.6-1.7 rocker on the intake.
The advantage of the 270's over the 240's is really in the mid upper lifts and with short duration you're probably not using as much of it as you could be. at low lifts you may have a bit less flow but you have more velocity with the smaller port, and as long as you can fill the cylinder adequately, velocity is torque, especially at part throttle.
but back to the intake, Fast68 and Firefighter back years ago tested both an unported 440-2D and a 337 MP single plane on Firefighters 572" RB and the 337 was about ~15 HP better. But the stock 2D made over 700 with just a 1" spacer if I remember right.
I still have the dyno sheets, I can look 'em up.
I wish they could have tried my ported Versions, I have one of each with a good bit of port work to each of them....and that big 572 would have taxed them a bit harder than my "little" 517.
If I had to pick a cam it would probably about 237-244 @ .050 and .580-ish lift, but in your motor with what you have, I think you'll be just fine, That the cam size I mentioned is in my buddy's 3800 pound CJ-7 with a 442" AMC (109 lobe centers). And that's with heads that flow about as well as an averagely ported Edlebrock SMALL BLOCK Head. 547HP/543 TQ and with a torque curve over 500 lb/ft as flat as kansas
It runs consistent 12.1's in the quarter on 33" mudders...and that's with the windshield up! I keep telling him it would go 11's easy without pushing that vertical Sail of a windshield through the air!!
I promise you that's haulin' azz with a 4wd...and when your butt is 5 feet of the ground it feels like 180mph, it's on my youtube site, just type in Wizerulz