What is the difference in the 3.9L and a 3.8L mustang? I just got a 2004 3.9L and wanted to do some exhaust work but unable to find 3.9L parts or does the 3.8L parts work for it?
yea it will work fine... its the same engine... ford ran out of the 3.8L so they had to go with something else so they went with the 3.9L... all the 3.8L parts will fit...If i recall right
What is the difference in the 3.9L and a 3.8L mustang? I just got a 2004 3.9L and wanted to do some exhaust work but unable to find 3.9L parts or does the 3.8L parts work for it?
It's externally the same engine, and the same chassis. Any of them will work.
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Woe to him who builds his palace by unrighteousness,his upper rooms by injustice,making his countrymen work for nothing...Does it make you a king to have more and more cedar?Did not your father have food and drink?He did what was right and just,so all went well with him. He defended the cause of the poor and needy,and so all went well...But your eyes and your heart are set only on dishonest gain,on shedding innocent blood and on oppression and extortion. Jer 22:13, 15-17
Also remember that if you want to see HP increase... you need to remove the Y pipe and go with nothing or X or H pipes... Also dont go above 2.5 inches... unless you have a power adder
3.9 just had a different crank right? which pushed the .1 liter.
I've heard two different explanations, but I think it was a crank. Ford wouldn't go to the expense of changing the bore.
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Woe to him who builds his palace by unrighteousness,his upper rooms by injustice,making his countrymen work for nothing...Does it make you a king to have more and more cedar?Did not your father have food and drink?He did what was right and just,so all went well with him. He defended the cause of the poor and needy,and so all went well...But your eyes and your heart are set only on dishonest gain,on shedding innocent blood and on oppression and extortion. Jer 22:13, 15-17
Actually the 3.9L is bored and stroked differently and thats how you get the extra like three HP, i have the same exact car and my buddy steve works at a ford dealership and thats what he said, he hasnt steered me wrong yet so i wouldnt doubt him. Just adding my two cents, but every part that says 3.8L will fit the 3.9L EXCEPT for if you were to add new pistons.
VR,
Travis Lewandowski
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1999 Ford Mustang Cobra Vert, Black with Tan top, mods: H&R sport springs, built '03 irs, bf brace, 4.56 gears, bushings, polished bassani catback with mac longtubes and O/R-H pipe, strange struts, bilstien shocks, centerforce dfx clutch, aluminum quadrant and firewall adjuster, caster/camber plates, polished and repainted bbk intake, ported lower by NAZ, mgw blue shifter, full length subframe connectors, arp extended wheel studs. More to come!!!
I have also heard that all the 3.8L mustang parts fit all the 3.9L mustangs as I myself just recently got a '04 3.9L and have been doing some research. I was having the same problem looking for a CAI and asked around so I ordered one that is for a 3.8L, but I haven't gotten the part to install it yet. I have been looking for a cheap exhaust fixture and found this >>> Pypes 409 Stainless Steel Street-Pro Catback w/ Polished 304 Tips for Factory Mid-Pipe (96-04 V6) at AmericanMuscle.com - Free Shipping!. Of course I would like to go with an X or H pipe, but I have a very limited supply of money with college payments and what not.
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2004 V6 3.9L Mustang (automatic)
Go: Fenderwell Cold Air Intake, Dual Exhaust (no crossover) featuring a MAC catback, SCT Mustang 4-bank eliminator chip (tunes by Justin @ vmptuning)
Show: Stainless Steel Bumper Insert Letters, 8" Chrome Shorty Antenna, Mustang License Plate Frame
God bless all!
I have also heard that all the 3.8L mustang parts fit all the 3.9L mustangs as I myself just recently got a '04 3.9L and have been doing some research. I was having the same problem looking for a CAI and asked around so I ordered one that is for a 3.8L, but I haven't gotten the part to install it yet. I have been looking for a cheap exhaust fixture and found this >>> Pypes 409 Stainless Steel Street-Pro Catback w/ Polished 304 Tips for Factory Mid-Pipe (96-04 V6) at AmericanMuscle.com - Free Shipping!. Of course I would like to go with an X or H pipe, but I have a very limited supply of money with college payments and what not.
your cai will bolt up fine, the engine has the same intake manifold
Hey, JDank, could you please share with me what modification(s) were necessary to install the 3.8 CIA on the 3.9 and the brand of CIA? Your help would be greatly appreciated. Thanks.
Will 3.8L exhaust parts fit a 2004 3.9L? 
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