Going to put a set of headers on my son's truck when I swap out his motor. Just want to get a little more umph out of his stock 318.

Anybody with personal experience, your opinion is welcome...

I had a set on my 75 W100 with a 318. Can't say if it gave any more power, but it sounded better!

Stock 318 the headers won't make any difference. Cam, carb and then headers.

89 should be tbi. TBI engines don't take nicely to flow modifications like cams and headers. if you sticking with the TBI system, don't bother wasting money on headers. If going carb, then small tube headers, preferably coated, are reasonable.

After running headers for years on trucks, I have stopped. There just is no value gain to them. They also don't last very long.

OK - I guess I will stick with stock manifolds. Does dual exhaust do anything for performance on these?

OK - Thanks. I appreciate the advice

best set is the hedman 79071 2x or 4x4 or the hedman 79080 for 2x only.

I prefer the 79071 on a 2x as the starter R&R with out moving header. and when the oil filter drops off it does not soak the tubes.

I beg the diff on a stock 318 not getting any boost in performance Just adding headers and duels.

that's what I do first. headers and free flow duels. advance the timing and adjust carb.

that was the best thing for the old LA BBD 2v carbed 318 IMHO.

the stock TBI roller cams respond well to a small 4v and headers as well once you ditch the electronics stock Ign.

then grab a stock 5.9 roller cam and toss it in with a carb/headers.

have it reground on the cheap or like all my lopo 200,000 mile JY engines go with the Hughes whiplash cam flat tappet or roller cam.

once I recurved the dist on the 440 whiplash it sounds like a pro-stock but drives like a 68 new Yorker around town.

my little pre-mag 318 whiplash roller was awesome with the NV4500 5 speed 3.55 gears in my stepside.
gone back to a CRT/TF-2 727 non lock up with a stock 10" high stall TC installed a e-body 8 3/4 with a 3.23 and is still awesome daily driving.

LMK you need parts. got plenty to trick one out.

carbs/intakes/headers/8 3/4 or 9 1/4

Aren't the roller cams the same in 318&360 tbi motors?

IIRC, no. 5.9/360 rollers as well as a 360 flat tappet 2v or 4v cam specs are slightly larger.

I would use a 360 2v cam in a 318 re-ring job.

if I had the 360 heads around to drop on a 318 I would up the teen cam to the 360 4v cam.

like I said not much difference but it made good running daily driver work truck engine.

340 cam is another good step up for a teen with 1.88/160 valves.

my best little teen was a 68 318 with a HiPo 273 solid lifter cam/stock 273 valve train with .500lift.

man that teen would buzz 6200rpm with the 4 speed/3.91/245-60/15

My take:

SFT is right, if you are talking long tube headers they make a noticeable difference all over, and not just at high rpm. If you are talking shorty headers I don't think they get you much. By 1989 the LA motors were both wearing the same exhaust manifolds and switching to dual exhaust or even one 3" pipe would help.

The 318 roller cam is smaller than the 360 roller. Sometimes. It seems that Chrysler was really playing around with the camshafts. I used a stock replacement 360 roller cam when I did my '86. Best data I had at the time was the '86 318 cam was 191/191 and 0.390/0.396, while the 360 cam was around 201/199 and 0.401/0.399, something like that.
One more thing you can do is regrind the 318 hydraulic roller, doesn't cost an arm and leg, less than $150 from at least two vendors. The stock lifters just go back on. SFT would tell you to disassemble the lifters and clean any crap out of the inside. I didn't do that, but if you decide to do that don't mix up the little pistons from the lifters as they are precision fit. Also when reusing the lifters I try to put them back into the same holes. There was an oiling hole halfway down the body on my lifters, take note which way they are pointing as you take out the lifter. I was never sure if there was a preferred direction, and maybe it doesn't matter at all.

Good luck in your project! we are here with more help when you need it.

R.