I had to look it up to cause I didn't no what it was at first too.

 

this is true, but also keep in mind that the 5.2 gets on the power and torque at a much lower rpm than the 4.7 does. That's where the extra 1/2 liter comes in (of course that come with worse gas mileage too). Of course the new 4.7s make over 290 hp and over 320 lb/ft of torque. The 5.2 also has many more performance add ons for it as well and was built for over 35 years so it is very durable. Don't think im saying the 4.7 is a bad engine or anything (it is very good), it just depends on what you want.

 

Yeah I have nothing against the 5.2s there definitly is more add ons because it has been produced much longer and its a lot friendlier to work on since there's less electronics. The 5.2 may make its power at a lower rpm but the 4.7 revs up a lot quicker and with the SOHC can handle a higher rpm with o/d on in my 4.7 if I step on it as soon as it gets over about 2000 rpm it really picks up and won't shift till about 5500 if I stay on it which is what I beleive the neutral rev limiter was set at or close to in a 5.2. On the highway if I step on it to pass someone going 60 I can easily hit 85+ by the time I can comfortably move back into the correct lane with stock size tires and no roof rack

 

On the dial the 5.2's redline is 4800 but I don't think the fuel shut off is until around 5200. The sohc doesn't have a much of a problem with valve float at higher rpm which is one reason why it can rev higher, the other being less reciprocating mass. All the engines in these trucks (except the v6 that was available in 99) are powerful engines, dodge definitely got that right. I know exactly what you mean about putting it down to pass someone, I've got going pretty quick before without really trying to while passing people before too. Gotta love V8s

 

Wow I did not expect the redline to be that much lower on the 5.2 on my 4.7 the tach goes to 7 and there's no redline on it and I've bounced the rev limiter a few times and I beleive its around 6500

 

Valve float isn't a huge issue on 5.x's cause they have hydraulic lifter cams.

 

Factory valve springs can only handle so much though its more dependant on the springs than the lifters I don't think a 5.2 would last too long over 6000 rpm. With performance springs though they can easily survive 7000

 

Why go that high? The power drops off so much at those rpm with out a cam upgrade or new heads.

 

I don't think the rest of the engine would withstand going that high without some serious modifications. You'd need lighter pistons, connecting rods, high strength crankshaft, camshaft, and all kinds of other stuff.

And i just mentioned the valve float since that is a common limitation not necessarily with the magnums but engines in general

 

I was just saying the hydralic lifters cams don't really help with valve float. And no you would not have to do all of that stuff. Yes it would help performance but its not neccisary unless you plan on holding that high of an rpm for an extended time. The 5.2s were a pretty tough motor and could handle a lot of abuse