What's the best header size for my 360?

[Littlestroker]

What's the best header size to use with a 360. I'm currently running the 1 5/8 headers with my combo.
70 dart
360 0.30 10.8 comp
360 heads 2.05/1.62 flowed
cam racer brown 520 lift/ 254@.50
Holley strip intake/750proform carb
4500 convertor/727 trans/4.56 gear/28.5X9.0
Race only. Thanks

[DartGT66]

Your current ones are a bit on the small side. I think 1 3/4" might be about right. When going to bigger than the regular 1 5/8" 's, it usually means race headers. They are usually also otherwise better designs, often equal length, better port openings and collectors, and that will help too. Personally I like relatively small primary headers, trying ot "tune" them to slightly above the rpm where your rpm drops at after shift. I'm using 2" primaries in my 780 hp 528 pump gasser.

[dwc43]

I have to agree with 1 3/4" tube size. Get a good set from Hooker or Hedman. You'll also need to wrap them with header wrap and dei spark plug boots to keep under hood temps down and to protect #5 and 7 plug wires.

[rumblefish360]

Double ditto. 1-3/4. I just don't know who for an A body.

[TK]

i got a ceramic set of supercomps out in the garage, illl go look and see if they have a #................
ok, heres what i got.............L (for left) 5901-07-04. this is stamped in the flange. my caliper sais the tube od is 1.81 im pretty sure 1.88 is 1 7/8, but im not sure how they measure these (i think they were spose to be 1 3/4)

personally, i dont think you will notice the difference between 1 5/8 and 1 7/8, at least with stock heads (just my oppinion)

[dwc43]

You will notice a difference too. Also moves the power band. Measure the inside dia.

[heigleracing]

1 5/8 is normal size for stock head. 1 3/4 or 1 7/8 will be considerably more expensive. with stock head or an Eddy head the expense of the large tube may not prove to be money well spent. for a W-2 head i would say that the larger tube would be absolutely necessary. Hooker does have a step header.

My opinion is based on combo's that I have had over the years. stay w/ 1 5/8 until you move on to a big head w/ some better flow.

[TK]

1 11/16" ID (snap guage)
im pretty sure these are 1 3/4 headers, cause they are for my tunnelram magnum 360 (and why would i order 1 5/8"?)

at least he can use these numbers to call hooker and see what is available. these are for a 72 duster (same headers as my 74)

[dwc43]

Originally Posted by dodgetkboy78

1 11/16" ID (snap guage)
im pretty sure these are 1 3/4 headers, cause they are for my tunnelram magnum 360 (and why would i order 1 5/8"?)

at least he can use these numbers to call hooker and see what is available. these are for a 72 duster (same headers as my 74)

Sounds like you might be right. I know going from a 1 5/8 to a larger tube will make a heck of a difference in the way a 360 runs. Anthing to help get the exhaust out really wakes these up. Dual pattern cams really help too.

[Littlestroker]

If I can pick-up a tenth, it's well worth it. I'm currently running dyno-max street headers and I'm not sure how tune they are.

[perfmachst]

hello, a step header is very good setup. either a 3 step or a 2 step will work.
3 step= 1 5/8, 1 3/4, 1 7/8 steps. 2 step= 1 3/4, 1 7/8. most stockers and super stockers run step headers. another combo is, an anti reversion style.
such as, 1 7/8 fitted with cones just inside flanges. I went from 1 3/4 to 1 7/8 anti reversion headers, worth 2 tenths and 2 mph in a stock eliminator 340. just food for thought.

[HNB racing]

go 1 7/8 primary tube your 360 will love it especialy with that converter your running

[Tarrbabe]

I use to run the Hooker Super Comps with the 1 3/4" on the street with 2 1/2 pipes and muffs. Ran great. Really came alive with muffs. off. I ran stock J heads on a 340.
Maybe a little soft on the low end but really good above 3000. That helped with wheelspin.

[gthomas]

Originally Posted by dwc43

I have to agree with 1 3/4" tube size. Get a good set from Hooker or Hedman. You'll also need to wrap them with header wrap and dei spark plug boots to keep under hood temps down and to protect #5 and 7 plug wires.

I took my car to a muffler shop and the guy told me that the wrapping I had on them will ruin my headers. At that point I had him unwrap a few inches of the tape and the metal looked crystalized. I had him take off all the wrap at that point. The headers were uncoated ProComps. Its possible that coated ones won't do that.

[rumblefish360]

G;
The coated headers should be fine for a long time. Driving in harsh weather will reduce the life, but should outlast the uncoated units hands down.
The coatings will fade off and may chip with road debrie hitting it. Touch up is all it should need at best.
Theres no need to wrap the coated header. Though the wrap reduces underhood temps better, there use in concert is not recomended by the coating manufactures.

I have wrapped up headers before. They do retain water for a time and will rust the header. Also, unless your dead on in even header tube temps, the thermo cycles with the wrap in off temp tubes can cause metal fatigue on the tube. Now weaker through many thermo cycles, rust eats better.

Never heard of "crystalized"

[dwc43]

Originally Posted by gthomas

I took my car to a muffler shop and the guy told me that the wrapping I had on them will ruin my headers. At that point I had him unwrap a few inches of the tape and the metal looked crystalized. I had him take off all the wrap at that point. The headers were uncoated ProComps. Its possible that coated ones won't do that.

Very possible. We remove the paint from ours and coat our own with Tech Line and then wrap them .I have a fav. set that's been around for 8 years now and still going strong. THey've been wet from cleaning,oil stained from a leak on right side, and been run hard too. Still hanging around.

[dwc43]

Originally Posted by rumblefish360

G;
The coated headers should be fine for a long time. Driving in harsh weather will reduce the life, but should outlast the uncoated units hands down.
The coatings will fade off and may chip with road debrie hitting it. Touch up is all it should need at best.
Theres no need to wrap the coated header. Though the wrap reduces underhood temps better, there use in concert is not recomended by the coating manufactures.

I have wrapped up headers before. They do retain water for a time and will rust the header. Also, unless your dead on in even header tube temps, the thermo cycles with the wrap in off temp tubes can cause metal fatigue on the tube. Now weaker through many thermo cycles, rust eats better.

Never heard of "crystalized"

Don't mean to argue, but header temps vary greatly at different rpm levels and even more so on a street car. If they fatigue from heat variance then they wont last long on a street car at all.

[rumblefish360]

Agreed. Can't argue that.

[coupe32]

I'm running Sanderson block huggers on my 340 in my street rod. They seem rather small diameter tubes. Just how much power am I giving up using these headers? They look good but I'm probably sacrificing lots of power. I havent looked around for anyting else that might fit in those tight spaces.

[dwc43]

Your giving up quite a bot of hp with those block huggers. They don't flow or scavage much better than a stock manifold does. Start looking for some long tube tuned headers.

[4406RR]

I WOULD GO WITH 1 3/4 TUBS or a step header you will start to lose low end with any thing bigger and factory heads