So I've done all the usual mods to my 03 SCrew 5.4 (pulleys, CAI, cat back exhaust, COP, e-fans and tune. I'm looking for more towing power, particularly on the low end 2000-2500 RPM to keep the truck in overdrive to bring my RPM down on the highway. What's next? Is there anything internal that can be done to these motors? I know the computers play a huge role in these engines does that make a difference when doing something like swapping to a different cam...would I be better off swapping a newer engine in?

 

depending on budget, i would choose long tubes. a cam could help but you'd have to get the right one or you could end up with less bottom end and more top end and worst fuel mileage and it would require custom tuning. and IMO they arnt worth the hassle unless you need to go into the motor/heads for whatever reason.

 

Stock 3V heads flow better than ported 2V heads. Just swap in a newer 3V engine and related wiring/computer. Doing a little head porting on the 3V heads and a comp cams cam for the way u want to run it. Put in a trans shift kit also. U can also swap in a 4V engine if u want.

 

For that price he could build a boosted dependable 2v that would eat a 3v. The 2v's are better built if you ask me.

I would say long tubes, head work and new tunes.

 

A 3V has superior heads to a 2V. Go to Livernois motorsports for 3V stuff.

 

Have you seen this done ? I have once, but there has been problems. I think he went with a 3V engine complete tho, from the manifold down in a 2V truck.

Got it to work tho. 4 valve/ Navi heads are out there. Navi swaps have been successful, but the 32 has it's share of problems. Iduno, I would probably stick with 2V heads, since you can get more than enough flow without breaking crap doing it. Well your still going to break something eventually, no matter what lol.

 

No, the stock 3V head dose not flow more then the ported 2V heads.
Also, it has been proven in many application that the 2V heads have better low end torque then a 3V head.
Yes, stock for stock, The 3V is a better performing head.

To the OP,
put a Lightning intake assembly on it. You'll have plenty low end torque then.
And cams are a wast of time unless you port the heads too.

Phil

 

After seeing the flow numbers I thought why spend the money on a 2V when I can get more from a 3V and cost less. Yes there will be problems but I can change stuff I need to when swapped. I've thought of a 4V but was cautioned it needs to be supercharged.

 

How can one intake passage flow less than 2? A 3V doesn't open up until rpm has built up. This gives u better response up to the point u open up the second intake passage and more flow and hence more power is produced.

 

Good info guys. Please keep the discussion going. I'm a Pontiac guy and can work on an old motor but these new fangled things throw me for a loop. I know they're probably not all that cosmic, but electronics are intimidating to me. Any one near Tampa that recommend a good shop for this kind of work?

 

EFI is so much better than a carb. I spent 15 yrs working on carbs and now I open my laptop to change/improve things.

 

I think you meant to say,(how can one flow MORE then two) Correct?
Sorry it took so long but I had to look it up.

Stock
3V lift____ intake___exhaust
.500 -----223.2-----148.2
.600 -----224.8-----153.7

2V stage 3 ported
.500-----226.3-----187.9
.600-----242.7-----204.5

 

Oops I need spell check. Thanx that's what I meant. The flow numbers show a 3V set of heads will flow like ported 2V. I would rather just go 3V all around.

 

First you say the 3V flows more then 2V ported. Now you say they flow like a ported 2V.
The 2V ported flow MORE then the 3V....lol
The 3V would be a nice setup. but theres a lot to change.By the time you make all the changes I think you'll spend just as much money on them as you would on ported 2V heads. Unless you drop the hole 3V motor in , and then theres still a few changes to be made.
Both setups have there advantages and disadvantages.
I like the 2V because you can bolt a Lightning intake on it and have a good supercharger setup.
But Whipple and Roush and a couple others have blowers to bolt on a 3V.

Oh,,by the way. Are you talking about swapping in a 3V motor, or swapping 3V heads on a 2V motor?

Phil

 

I see your side but I can't see shelling out the money for ported 2V heads when 3V heads are close and I can get a whole engine for less. I like the twin intake passages. It's like a staged 2 bbl carb. All the stuff now is for 3V any ways. Yes I would like to swap in a 3V. The only problem I see is the IMRC but it is in my tune.