Just bought a 5.7 for my Duster

I don't know if the 2003 5.7 Hemi is anymore desirable to work with than other years. I would consider all 2003-2008 to be nearly the same in overall terms of durability and hot-rod ability.

The 2003 Hemi's had two computers one for the engine and one for the transmission, all Hemi's use a drive by wire setup, though the 03 had a standard pedal that actuated a cable that pulled on a box under the hood that sent an electrical signal to the computer, which then sent a signal to the throttle body either opening or closing it.

Some later year hemis are a bit more difficult to hot-rod because they had cylinder deactivation, this began in 05 for the cars and 06 for the truck engines. 2009 and later saw the introduction of revised cylinder heads and cam phasers that allowed the computer to adjust the cam timing to improve mid range torque and horsepower. The later 09 Heads are superior to the 08 and earlier heads flowing about 20 CFM more on the intake side. Stock 09 heads flow about 295 CFM on the intake side vs 275 for the 08 and earlier heads. 2008 and earlier heads can be ported to over 300 CFM with stock valves and into the 320 range with larger valves.

I don't have a particular recommendation for cylinder head but Stan Weiss has created a database of cylinder head flow number on both the 5.7 and 6.1 hemi heads. You can read it here:

http://users.erols.com/srweiss/tablehdc.htm

The stock throttle body is 80mm if you are going use the drive by wire and the factory computer, you have three basic choices. Stock, 85mm and 90mm aftermarket, though Kennebell makes a giant drive by wire throttle body for their blowers.

Here are a couple of links to throttle bodies:

http://www.shophemi.com/c-488-hemi-throttle-bodys.aspx

http://www.kennebell.net/KBWebsite/Accessories_pg/Mammoth Dual 1880/layouts/mam1880.htm

Camshafts, I am probably going to run one from hughes engines, they offer re-ground cams at really good prices, which is an important consideration for me. The limits for a stock hemi lower end is about .550 lift anymore and you are likely going to run into piston to valve clearance issues. Here's there camshaft page:

http://www.hughesengines.com/Index/...3LzYuMSBNb2Rlcm4gSGVtaQ==&level1=Q2Ftc2hhZnRz


My preference is to retain the efi, yes the learning curve is a bit steeper, but why degrade a motor? I think once you learn EFI you'll wonder why anyone would ever build a carbureted engine.

Regards,

Joe Dokes