kcorpetti

Yeah im asking about headers for a 3.4 swap. I have the engine out, so I just need to know which ones fit...!

Texas_Ace

Ah, can't tell you that one, i know the doug thorleys fit like a glove in a 3rd gen. Not sure about a swap. With the engine out the install would be easy as well.

PismoJoe

JBA makes a set for them, I would bolt it on before dropping the engine in. There is a crossover bolt that is hard to get to with the engine installed.

kcorpetti

You mean a set for the 3.4 swapped engines?

PismoJoe

I mean a set for any 3.4l 5vz-fe, so yes if you swap one into whatever vehicle....

camo31_10.50

it's not the motor Joe, it's the clearance of everything AROUND the motor..

vital22re

iTrader: (2)

title edited and moved to 3.4 swaps. You're taking a motor that the exhuast was designed to drop on the passenger side and put in rig that drops on the driver side. The clutch slave cylinder on 5spds will be an issue. Maybe on an auto it will be okay.

PismoJoe

Ohhh got it haha I thought he just wanted a brand

kcorpetti

Thanks for the aclaration, vital22re.

Yeah, im looking for headers that would work on a swapped 3.4. What do you guys think of custom-built ones?

S.C.YoTa

the exact problems i had on mine thats why i sold it . i had the obx brand.

aa1911

iTrader: (1)

I love my doug thorley shorties, pricey and won't give much gains by themselves but are a beautiful combo with a SC... as for stuffing in a 2nd gen... mmm... my same dilema here this summer when I do my 3.4 swap (+SC)... don't think they will fit according to what I read from others' experience...

The stock headers will flow OK w/ a SC but performance headers do give better flow thru the engine, increases volumetric efficiency... they (in theory anyway) 'pull' exhaust gases from the cylinders as they fire... they do sound beautiful also, not too loud but still robust.

I would be curious to see if anyone can make these aftermarket headers fit in the 2nd gen 3.4 swap, seems like a near impossible task... does anyone know if a custom crossover pipe will A) fit reasonably, B) retain the headers' full capabilities??

aa1911

iTrader: (1)

If you can (or know a shop that can) fab up some custom headers, you don't need very large diameter pipes but just equal length primary tubes, would be sweet if someone would start making some "3.4 swap" shorty headers to work around the clearance issue...

Texas_Ace

The doug thorley headers were dyno proven to make 15hp more on an NA truck, the dyno is floating around someplace. Never saw the numbers for a SC truck but they would be higher.

sirhk100

The hardest part of pulling my headers off right now is removing my steering shaft and that's only cause mine is wedged in there from making it about 1/16" too long. Other then that I can pull the headers on and off my truck in nothing flat! I'm guessing the inner wheel well or something is what you guys fight with that makes it so difficult? I don't have that so access to them is a breeze thru the wheel well.

Also, my headers clear the slave and fork on the pass side with no issues. I did wrap them with header wrap to try and keep the heat down around where the rubber boot for the fork is and the boot on the push rod of the slave cylinder though.

Fitment wise, I did cut the outlet on the pass side and rotated it a little to index it away from my frame rail cause stock it rested right against the frame. On the drvr side I had to put a "custom dent" in the forward tube to clear my steering shaft but I think that's cause my truck is built around a 3" body lift so the steering shaft isn't running thru where the stock location would be.

Overall though the headers were by far one of the eaiser parts of the swap... I do still need to take it to the exhaust shop to have a "Y" pipe built to connect the headers to my tail pipe though.

theMonch

I have the Downey's on my 3.4 1st gen S/C swap for about 7 months now. I absolutely love the sound and they make great power. I went straight from the 3.0 slow mildly modded to the 3.4 S/C headers w/ URD 7th injector, so I don't know if they made adiffernce over the manifold, but I can tell you they sound very intimidating even though they go back to 1 pipe at the converter. You can read all about the clearancing that I had to do (not much) to get them in there in my build thread. I also had a custom 2 into 1 crossover custom made with an integrated HP cat and had 2 1/2 stainless from there back with the old 3.0 setup that I kept. There is a vid in my build thread in my sig that has them running open right after I got the swap up and running.

MaK92-4RnR

alrighty... well... lets make a discussion about what the headers HIT when you put the 3.4 into a 1st, 2nd and 3rd gen truck and 1st and 2nd gen 4runner? because I was told that the downey's and Doug thorleys dont have a fitment issue when they are used on a 3.4 swap.

vital22re

iTrader: (2)

then add 2wd vs 4wd

theMonch

I can only speak for my 1st gen 4R experience, but here is what I experienced. Again, it is a 88 with a 97 3.4.

The drivers side comes incredibly close to the steering shaft. I had to remove the plastic cover that protects the joint. My Downey's had the provision for the EGR option so I had to cut off that flange and weld up the resulting hole.

I had to fabricate a custom alternator lower bracket so the alternator can be run imboard more towards the center of the engine. This could be because I an running a high AMP NWR alternator, but it looks to be not that much bigger than the stock 3.4.

I had to cut the heat shield that protects the torsion bar mount and upper control arm bushings. I had to take out about a 2" x 4" section.

I had to tweak the heat shield that protects the firewall down by where the firewall wraps under the truck.

On the passenger side I had to tweak the fuel hard line coils toward the frame a little to get them out of the way. There was also a heat shield on these that I had to remove altogether.

The passenger header dumps right next to the slave cylinder in a 5-speed application, so I could not have flanges mounted to the headers. Instead I used band style exhaust clamps and slip on joints to the headers. I have had no leaks so far with 7 months and 7k miles.

sirhk100

'89 2wd pickup. 3" body lift

Mine is bare minimum up front though. No torsions, no inner wheel well, etc...

Drvr side hit steering shaft and also a heat shield.

Pass side hit fuel line and rested right against the frame rail.


I moved, cut, removed, modified, etc to clear what was needed...

UKrunner

I have stock manifolds ported slightly and port matched to custom 2 inch dual down pipes that "y" under the transmission bell housing. These then join a 2 to 1 collector and run down the same path as the stock 3.0 exhaust. All I have is the single stock 3.0 muffler - no cats.