Long Tube Headers - '66 289 (347ci)

[hivewax]

hello all. i'm in the lingering process of stroking orig 289 block to 347ci w/AFR185 heads, 600cfm Holley 4V, manual 4-spd... just for the streets + highways. what long tube headers fit my application w/out hitting speed bumps + having spark plug access? 1 5/8" or 1 3/4" primaries? options: Jet Hot Hooker Competition, JBA's, Doug's, FPA, Hedman

 

[htwheelz67]

I'd run the dougs try y-s , 1 5/8 is fine dont go any bigger for a street car.

 

[302 coupe]

if you're gonna choke it with that puny carb, you might as well run stock manifolds.

 

[hivewax]

the 600 cfm Holley was the decision of the machine shop. i thought it was small too, but they said different.

i also wanted side exhaust, but want to hear my radio. what muffler works best. DynoMax Bullet? or, Spin-Tech's?

 

[jbuening]

If you have the money, give FPA a call. Only full length header that I know that won't create ground problem clearance issues. You pay for them though

 

[hivewax]

i read that the FPA header clears a cable clutch. will it clear the orginal setup... all manual 4-spd?

good thread -
http://forums.stangnet.com/showthread.php?t=711186&referrerid=100091

 

[Robdogg67]

I second FPA longtubes, they solved all my issues and my tranny pan hangs lower than the collectors. They'll last you forever too.

 

[hivewax]

i'm deciding Doug's or FPA. i'll give both a call to confirm easy installation. for the rest, i'm narrowing down to Spin Tech race mufflers w/ their various oval pipes + X-over. the sub-frames on my car are the same depth as the frame rails under floor plan (approx. 1.5").

http://drgas.com/store/product.php?productid=47&cat=9&page=1

i'm just concerned on loudness + ground clearance.

 

[fasttback]

will it clear the orginal setup... all manual 4-spd?

If you are referring to the z-bar linkage = no. I wish it did though.

 

[coolblue65]

I have Hooker Comps, and I am happy wit the fit, Spark Removal isn't too bad, just have to watch your spark plug boots so they don't touch any headers. They hang a bit low, but I rarely scrape them- and my car is lowered too.

 

[fastback brian]

I got my 1 3/4 long tubes from accufab.....cost about $500. My big bore 347 spec'd out for a custom 980 carb.....

 

[valley firearms]

carburetor

If you are doing a 347 and using the 185 AFR's you had better run at least a 750. If you put that 600 on there you may as well stick with the stock cast iron heads.

 

[hivewax]

thanx all for the input. i'll talk to the shop again about the carburetor size and how they came up w/600cfm.

 

[Decurion]

The FRPP catalog says their 347 makes 450hp using a 650 carb, but the Roush (who does a LOT of work for Ford) engines that range from 327ci/350hp all the way up to the 427ci/550hp all use a 770 cfm carb. Personally I think the 600 would be a restriction, unless you have a pretty small cam. I would go with a 650 for the best combination of low end torque, streetability and overall performance.

 

[hivewax]

okay, just talked to the shop. 650-660cfm is the largest carburetor they recommended... Demon 660cfm or Edelbrock Thunder series. the specs for the cam will be getting today. which carburetor do you all think is best for my 347?

 

[hivewax]

Camshaft

here are the specs for the cam i'll be using...

Application: Street/Strip

Comp Cams 31-242-3 "Xtreme Energy" Hydraulic flat tappet camshaft. Fits 1963-1995, 289-302 cu.in. Ford V8. Comp Cams "Xtreme Energy Cams" are the latest series of hydraulic cams to take advantage of the newest development of camshaft design and valve train technology. They have an aggressive lobe design that produces better throttle response than other cams with the same duration and they still deliver strong engine vacuum. "Xtreme Energy Cams" can be used for any street or street/strip application where both top end horsepower and good throttle response are desired.

RPM Range: 1,600 to 5,800 rpm.
Duration at .050" lift: 224/230 (int/exh)
Valve lift with 1.6 rockers: .509"/.512" (int/exh)

 

[SoCalCruising]

The rule with carbs is to go a little smaller rather than a little bigger than what you think your motor might need. I have Webers now, but I used to run a 650 HP series on my 331 (same heads, more cam, so not a bad comparo) and had plenty of fuel to 6000 RPM. BTW, I started with a Carb Shop 750 and went down to the 650 for better performance. A 600cfm carb is on the small side, but would give you wicked throttle response and enough fuel to 5500-6000 RPM. If you won't hit that number but rarely, then don't worry about running a smaller carb.

 

[coolblue65]

okay, just talked to the shop. 650-660cfm is the largest carburetor they recommended... Demon 660cfm or Edelbrock Thunder series. the specs for the cam will be getting today. which carburetor do you all think is best for my 347?

Well a Demon 660cfm will cover your engine, Demons are wet flow tested were as other carbs are dry flow tested, meaning a 660 Demon flows more cfm then a 660 Holley or Edelbrock.

I run a Mighty Demon 650 on my 347 (No choke, mechanical secondaries) - its nearly perfect, the car is a monster (110mph in the quarter) and still gets 21 mpg on the highway!

 

[hivewax]

Exhaust Setup!?

i'm undecided... show me your setup.
what do you all recommend for the exhaust past long tube headers??

- side exhaust is too loud and fumes come up thru the side windows.
- Dr. Gas X-over + pipes are not stainless steel. will they last?
- MagnaFlow has a nice setup, but goes straight out the back. doesn't have a kit for a GT.
- is their a brand that has a kit for a GT valance?

 

[blown65]

http://www.ponycarburetors.com/default.asp?page=calculatingcfm



I had one professionally size by ProSystems for our 370 CuIn 14-1 motor. Taking into account pretty much everything it pencils out to right about 830 on paper. Its got a 900cfm carb on it.

My 347 pencils out to 763 and its running an 830. I would say that calculation is pretty close on that web page. That being said if your only going to turn 6k on a 347 you really are fine with a 600-650cfm carb, any larger is probably not needed. IMO at least.

1 5/8" inch long tubes should be sufficient, heck thats all I'm running right now but I do plan to change that. (I turn 7600-7800 rpm though)