How restrictive are the stock logs really?

[65Bird]

Greetings all--new to the forum and to the FE.  Subject line pretty much sums up my question.  Given all of the horror stories I've heard and read regarding header fitment on a Thunderbird, I'd really prefer to stick with the stock exhaust manifolds and have a proper 2 1/2" exhaust system with h-pipe built for the car.  BUT-- since so many folks here and elsewhere believe the stock logs are such a choke point--I wonder if they would largely negate the impact of installing an upgraded intake like the RPM and a decent set of heads, even with a free flowing exhaust from the manifolds back?  I'd appreciate any and all insight!

[cjshaker]

Very restrictive. I doubt you could find a more restrictive manifold on just about any Ford engine. There are 'shorty' headers out there that would do a decent job, and be much better than the factory stuff. I know Sanderson makes some for your car, and I think there's another big name maker, but can't remember the name offhand. I was looking at them for my '65 Galaxie, and they had good reviews, but they said that a mini-starter must be used (not sure about the Sandersons though). A mini-starter would add to the cost, so I guess it depends on how much you're wanting to spend. Wish I could remember the name of that other brand. 

Edit to add that there are a number of 'no name' shorty headers out there. I'd stay away from them because everything I read about them said that fitment and quality sucked. Some of the pictures I saw of the quality were horrible. Missing welds, crappy welds, bad leaks etc.

[65Bird]

Thanks!  I think the other brand you're thinking about is FPA.  But those headers are also the source of some frustration in the Tbird community--requiring shimming of the motor mounts etc.  I gather the fit is so tight the install is best done with the engine out of the car--and even then modifications are required.  Sounds like an enormous PITA!  Guess I'm questioning the potential reward

[My427stang]

I would base it on how you drive it.

They are horrible, but if you only go for quiet cruises around the country roads, you may only be giving up gas mileage. In that case a distributor recurve, the dual exhaust and maybe a shift kit would make the car feel stronger.

If you are trying to make any significant power, I'd deal with the difficulties of installing headers, that is if the engine has been apart sometime recently.  If it hasn't, I'd be hard pressed to try to break loose the top exhaust bolts without a good reason and certainly not without heat and in that case, you are likely better waiting until the next rebuild

[JamesonRacing]

The exhaust manifolds on your T-bird have 2" outlets, so adding a larger diameter exhaust system is of little benefit.  Later model car/truck exhuast manifolds were often 2.25" diameter, so that would help a little, though you would have to fabricate a new H-pipe to fit.  The headers would be a much better option if you feel the need to make more power.

[RJP]

I would base it on how you drive it.

They are horrible, but if you only go for quiet cruises around the country roads, you may only be giving up gas mileage. In that case a distributor recurve, the dual exhaust and maybe a shift kit would make the car feel stronger.

If you are trying to make any significant power, I'd deal with the difficulties of installing headers, that is if the engine has been apart sometime recently.  If it hasn't, I'd be hard pressed to try to break loose the top exhaust bolts without a good reason and certainly not without heat and in that case, you are likely better waiting until the next rebuild

That is key to the use of these manifolds or not. Not everyone is looking to extract every last HP from their engine. And in defense of these manifolds I use the same on my 66 Galaxie Q code. [428-4V] They work fine for their intended purpose, no issues such as leaks at the flanges, blown out gaskets or anywhere else for that matter. The cost for a set of headers from FPA [The only co. that I know of that makes a header for your Thunderbird would be very prohibitive for the ROI. My 4200+lb Galaxie gets 15.5-16 mpg hiway... around town? Not so much. You most likely will notice little to no difference in HP/tq below about 35-3800 rpms which for an exclusively street driven vehicle is IMO fine and going to the trouble and expense of headers, with supporting exhaust system would be, again, IMO a waste of $$$ unless you have other plans for the car. As far as mods done to my Galaxie it has C1 heads with 2.09"/1.65" SS valves, solid lifter cam [old factory 406] C7AE-F PI aluminum manifold and a 600 Holley. Ignition curve was also tweaked. Trans is a lightly modified C6 and a 9 3/8" rear with a 2.75 ring/pinion...Makes for a nice highway cruiser with enough power/torque to keep things interesting and fun.

[thatdarncat]

Welcome.

Jay did exhaust manifold dyno testing also for his “ The Great FE Intake Comparo “ book, and, like Doug said, it showed the flat exhaust manifolds are really bad. And like Jameson said, I think he found Ford made a change to a slightly larger outlet on the redesigned C8 car manifold, I don’t know if anyone has tried fitting those on the earlier T-Bird chassis. Shameless plug for Jay’s book if you want to read up on it  So yes, just give some thought to how you intend to use the car.

Not the same I know, but just my experience, I own a ‘69 T-Bird with a 460 a friend of mine bracket races, and we used the FPA shorty headers for that, pretty sure they were the only choice for headers. I did the header install with the engine in the car. There was one tube we had to dimple for clearance, I think on the passenger side. I also had to use a couple flat washers to shim the motor mounts, between the block & mount if I remember. It really wasn’t too hard to do, just tedious to keep checking the clearance. I don’t remember anymore if I just carefully jacked up the engine, or used the hoist, but in any case it was try something, check, repeat, until it fit. Probably had a couple evenings of work into it, but it wasn’t too hard. But of course it’s a different chassis & different engine, so take that for what it’s worth. I’ll also say I’ve seen the comments from people on the FPA headers, various vehicles, that either fit perfect, or some might need an “adjustment”, just the nature of headers in a vehicle with a tight fit. Otherwise the quality of the FPA headers were fine. I’ll add too, I saw someone recently on another forum comment that Stan at FPA told them he may retire from the header business in the not too distant future, just a FYI. That would be unfortunate because he has quite a few headers for Fords no one else supports.

[cjshaker]

I would base it on how you drive it.

That is key to the use of these manifolds or not. Not everyone is looking to extract every last HP from their engine.

All of that is true, but then why spend so much money on the aftermarket heads and intake? Factory heads and intake would be good enough for a good street car, and then the OP would save $2500. I don't understand why someone would go to all that expense for parts designed for performance, then choke it with factory manifolds. I don't think shaving 150 lbs on a 2 1/2 ton car would justify it either. Not trying to argue, just saying it doesn't make sense, to me anyway.

[65Bird]

Sorry--I should have specified that this is strictly a street car.  No engine rebuild in the plans.  Also--I used the intake/heads example to gauge the futility of trying to make more grunt using the stock logs.  From the responses thus far, I'm getting the distinct impression that without headers, I shouldn't bother with any engine mods other than a re-curved distributor.  And I'm perfectly fine with that--guess I was hoping for an easy way out
 

[My427stang]

I would base it on how you drive it.

That is key to the use of these manifolds or not. Not everyone is looking to extract every last HP from their engine.

All of that is true, but then why spend so much money on the aftermarket heads and intake? Factory heads and intake would be good enough for a good street car, and then the OP would save $2500. I don't understand why someone would go to all that expense for parts designed for performance, then choke it with factory manifolds. I don't think shaving 150 lbs on a 2 1/2 ton car would justify it either. Not trying to argue, just saying it doesn't make sense, to me anyway.

I agree completely...the intake is likely all I would do for weight and even then I wouldn’t break the seal without a reason.

[66Bird]

I have a 66Tbird and feel your pain. Years ago, I wanted a little bit more horsepower and snap to my car. There is very little to choose from out there for headers. I went out and purchased a welder and a bunch of mandrel bent tubes and built my own 1.625x28" long tube headers. The headers took me a winter to build. It was worth the headaches. The headers along with a 268 cam, and a Pertronix ignition woke the car up, but still idled like stock. Best improvement that I've ever done to any car over the years. It came ALIVE! The original log exhausts are junk. They can't breath. Dan

[TomP]

As far as I know Stan doesn't build the headers, it is a local place near him that does so there may still be a source when Stan retires.

I put way too large 1 7/8" to 2 1/2 to 3"  TriY headers on my 332 when I did the 6V swap. Huge difference. Those earlier logs (575--- number) are even smaller outlet, maybe 1 3/4", each of the three carbs was bigger than the original one. The gains came at any RPM

[Rory428]

You do not need to be revving the engine very high, or be "Looking to squeeze the last HP out of the engine" to notice the improvement headers make over the terrible FE log exhaust manifolds. Years ago, I got tired of replacing cracked log exhaust manifolds on the FE in my 74 F350, so I installed a new set of Hedman long tube headers , along with a basic dual exhaust system. The performance gain was very noticeable, basically from right off idle and up. I rarely revved the 390 over 3500 RPM, freeway cruise RPM was typically 2600-2800 RPM. Although the headers never leaked, I did replace them after 14 years, just because they were looking pretty crusty, but when I removed them, they were still quite solid. I realize that a Ford truck has a totally different engine compartment, I was just commenting on how badly the stock logs choked power, even at low RPM on a basically stock engine. Regarding FPA headers, although Stan has them made by an outside source (In the USA!), that does sell their own line of headers, the FPA headers are not available from that manufacturer, as they are exclusive to FPA. I know the 61 thru 66 TBirds have very little room between the towers, possibly even tighter than a 67-70 Mustang or 66-69 Fairlane, especially with the 2 bolt exhaust pattern,and I have never installed a set in a TBird, but I do have the FPA headers  that are made specifically for the 57 thru 59 Ford cars with FE engines, in my 59 2 door sedan, and the quality is very good. Nice thick flanges, which are available with either the 8, 14, or 16 bolt exhaust pattern, and with either the higher or lower factory exhaust port location. I am not aware of any other header company that offers that. The mainstream header companies usually slot the upper bolt holes, and either don`t know, or don`t care, that FEs have several different exhaust port configurations. The FPAs are not "off the shelf" headers, you have to order them directly, and tell Stan which style of heads you are using, and then the headers are made to your application. Mine took about 3 1/2 weeks to arrive after placing the order, they even have my name stamped into the flanges. Certainly not cheap, compared to the mass produced headers made for much more popular vehicles. but as far as I am concerned , it was money well spent. Most of the FPA headers are very low volume, not very popular applications, that nobody else makes headers for. I am thankful that FPA was able to service this niche market.