headers vs manifolds

[charger500rt71]

 I'm in the process of putting my RT together and I would like everyones opinion. The engine I have  for the RT came out of my 71 500 that I sold. I switched to a hyd. cam with crane adjustable rockers, six pack intake,bla bla bla but still retains the Edelbrock aluminum heads. The question for you all is, should I run the factory magnum exhaust manifolds or a set of TTI headers? This RT Is going to be a cruiser not a 1/4 mile car {those days are over}Thanks.

[69wannabe]

Headers for sure dude!! You got alot of performance parts on there it sounds like, putting manifolds on this engine would be a terrible match I believe. I put a set of TTI's on my buddys 68 498 cubic inch and they fit nice!! They went right into place with the engine in place although I had to jack it way up to get the old hooker headers off of it.

[AKcharger]

I like the quiet of manifolds...yup costs some power but it's worth it to me

[BLUE68RT4ME]

I kept the HP manifolds to retain the stock look and had a custom cam designed by Ron (Firefighter)'s friend Dwayne Porter at Porter Racing Heads (I think that's it, or just Porter Racing).  He designed the cam to minimize the rough idle therefore hiding the fact that I had beefed up the motor.  It runs great.

That said, if you've already bought Eddy heads, you're obviously not concerned about the appearance of being stock.  Therefore, you're going to find it much easier to buy a cam for your motor including headers.  If you've got the heads your investment is not fully realized if you stick with the manifolds.  You're engine will run much more efficiently with headers.  With headers and the heads, you won't need a crazy cam to meet your needs but you won't have as many complications finding and selecting a cam either.

My friend bought a Road Runner to restore in which the 383 was already rebuilt.  The guy bought a radical cam and stuffed it in behind the stock manifolds.  It ran terrible and caused all sorts of complications which my friend didn't finally figure out until well after he spent more than the cost of headers.

Even if you stayed with the stock cam if you added the headers to the heads you have your engine will have more torque, HP, and better mileage.  I just can't see a reason to go with the manifolds in your situation.  However, this is only my opinion.  Best of luck and let us know what you decide and how it turns out!

Mark

[Cooter]

There USED to be a time when the age old arguement would hold water that manifolds are WAY less trouble than leaky, headers. Not true today with TTI.

They can be had coated for long life, and many times, come through with 3/8" Flanges for leak proof sealing.

Of course, there is NO manifold OEM, or after,market that will flow with headers for increased HP, Torque, and MPG.

[bill440rt]

If you're looking to squeeze maximum performance with those heads, yes then headers are the way to go. As good has HP manifolds are, they don't compare to modern headers.

However, if a stealthy stock look is what you're after in just a cruiser, the HP manifolds will work fine for that situation too. I have them on my 440 in my '68 with Eddy heads. I had them Jet-Hot coated inside & out, helps a bit with temps and exhaust flow. The straight-plug design of the MP heads are probably a better fit, but I have no problems with the Eddy angled plug design. If you run across a tight plug clearance situation Firecore sells little heat shields for this problem. I went ahead & painted my Eddy heads too, most passerby's really don't notice them at all unless I point them out.
Performance-wise it would be faster with the headers, but still compared to the crappy worked iron heads that were on it before it's a MUCH better improvement. 
Plus I can retain the stock "sleeper" appearance I was after.
Good luck with whatever you decide. 

[charger500rt71]

I've always ran headers with my engines, from a blue printed Max Wedge to a 440 stroker with 915's. I ran this motor for a couple of seasons with 2" Hooker Comps and she made good power, ran a consitant 11.80 in my 500. Will probably go with TTI or Dougs, like the idea of going stealth though.

[bobs66440]

Heddman Shorty headers. The best of both worlds. They are between manifolds and long tubes in power output and give LOTS of room to work on the engine. Mine have been on over a year and 3000 miles. They don't leak and still look great! 

[firefighter3931]

What cam did you install in the 440 ? With restrictive exhaust you need a cam profile with a wide LSA (112* or more) to reduce overlap. There are several off the shelf grinds that are "manifold friendly" 

Cam selection is critical if you hope to run/tune it properly with manifolds. 


Ron

[charger500rt71]

The cast iron manifolds were just a thought, headers are my only real option with the cam I'm using. Comp Cam Extreme Energy 295/519 on the intake and 306/524 on the exhaust is just to much cam for stock manifolds. My next exhaust question is should I buy 2" or 1 7/8" headers? leaning towards the 1 7/8. Thoughts?

[firefighter3931]

From my experience a 2in header is best suited to a race 440 or street/strip stroker. When we had my old 446 on the dyno we tried both sizes 1 7/8 vs 2in and they both made the same HP but Tq was 20ftlbs weaker across the board. This was a well built/machined combo (e-heads/solid cam) that made 535hp/540tq on pump swill.

A street cruiser will spend most of it's time in the 2000-4000rpm range so focus on those parameters. 


Ron

[charger500rt71]

I"ll use a 1 7/8 for this car with a 3'' exhaust, not building a 1/4  mile racer. Thanks.

[firefighter3931]

I"ll use a 1 7/8 for this car with a 3'' exhaust, not building a 1/4  mile racer. Thanks.

Good choice 


Ron

[Rolling_Thunder]

Personally I like stock manifolds - but your application needs headers.