I'm asked alot what the differences are between the 4.7L High Output and the 4.7L Magnum. Here you go.

1. Block - Detonation sensor bosses in the valley
2. Camshaft - custom profile lobes (designed for increased performance)
3. Connecting rods - modified, with floating wrist pins (vs pressed-fit pins in standard V8)
4. Crankshaft - forged steel (vs cast iron in standard V8)
5. Crankshaft damper - unique to H.O.
6. Cylinder heads - different shaped combustion chambers (for improved airflow). The letters "H.O." are cast on the front end of the heads.
7. Exhaust tip - chrome (2002 models only, decontented for 2003 models. Available only as a one-piece assembly with muffler)
8. Fuel injectors - higher flow (+3.3 lb/hr)
9. Intake manifold - modified (shorter runners)
10. Intake - low-restriction intake system (different resonator, air filter, air filter hose and housing)
11. Knock sensors - two, stereo
12. Main bearings - tri-metal (vs bi-metal in standard V8, designed specifically for the HO engine)
13. PCM calibration - unique programming
14. Pistons - dome shaped for increased compression ratio
15. Spark plugs - platinum tipped
16. Valves - unique exhaust valves (same lift as standard V8)
17. Valve springs - upgraded valve springs (intake & exhaust. Larger diameter wire and more coils)

http://www.wjjeeps.com/ho_engine.htm#DIFFERENCES

 

After all that they could only squeeze 20-30 more hp than the other 4.7s?? Slackers..

 

Yeah man, only more horses. The two best items IMHO are the cams (20hp) and the pistons (allow slightly more boost). Hence why in 07 they decided to redesign the 4.7 into what the 08s and newer have.

 

20-30 horses is a lot to me. better fuel economy?

 

Yea, but not for the RT edition with all that extra **** they changed for it.

 

out of those 17 things listed ive broken 6 HAHHA

 

For all the magnum owners, I've checked, it is possible to turn your 4.7 magnum into an 4.7 HO, however, given the cost, not worth it IMO. I'll just keep researching the 440 swap I want

 

Joe I remember that man. That was the underdrive pulley problem you posted about on dak-dur.

Pyro, thats cool man. Next year I'm looking at another large tax return due to three months of this year I spent in the middle east (tax free). I'm going to forge my internals, add ported and polished heads and go to the 2.75" pulley (18psi). My goal, 500 RWHP in a 4.7L and I believe its totally achievable.

 

500rwhp should be achievable, although if I were you, I'd build up the transmission to handle the power. That kind of power in a 4.7L shouldn't be an issue with the proper build up. Hell, some of the old Porsche 4.7Ls have been boosted up over 800hp, I think you could do it. Just gotta spend the $.

 

So far so good. Still on my to do list.

1. Intercooler with BOV
2. Stall Converter
3. Tranny Valve Body
4. Electric Fan

Next year.
1. Forged Internals
2. Ported & Polished Heads
3. Forged Crank
4. AIR-RAM Aluminum Intake
5. 2.75" Blower Drive Pulley = 18psi
6. Still considereing KRC Blower Grind Cams = 224 grinds