Flowtech headers, any good?

BlackFox5.0

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Aug 7, 2000
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I have a set of these on my other block, at least thats what I think they are.

They have pretty large primaries, which are oval shaped. they are full flange as well. The only thing I don't like about them is the header bolt clearences. They were installed with allen head bolts, some of which were grinded down to fit. Also the mounting side of the flange didn't look so good to me. At the ports they are raised, like the welds were not grinded smooth. I saw a pair on ebay that said these were a sort of "o-ring seal". It sounds like a good idea, but I don't know about how well it would work...Any thoughts? I need to replace my Mac headers, the studs for the h-pipe have rusted to nothing.
 
ive had good results with the summit, just quality control sucks ass. on my first set they went on very easily but one header tube (cylinder 8) would just slightly tap the steering shaft when the wheel would be turned. I also had to clean up the ports, the welding was pretty bad. on my most recent set, the ports looked great. but, when i went to install, one of the tubes (cylinder 5) was bent too far in and the header would not sit flush on the head. had to grind a small part (1/4 in) of the motor mount bracket for it to fit. THEN i had grind/cut the flange so the bolt would slip in from under. THEN had to pound the header right near the port so the bolt would have enough room to spin (tighten).

Other than that, they fit great!!! LOL
 
I have a set of their block hugger headers; I'm gonna need to try the right side header on mine to gain some clearance for a larger head pipe. The quality looks about right for the price in my opinion - low price, low quality. I've got a lot of weld cleaning up to do with the grinder, and I'll take it to a machine shop and have the flange milled flat. Not only is it not 'true' (a straight edge laid across it has a good 1/16" gap at one end - can you say header leak?), but those raised 'o-ring' seals don't look like a good idea to me. All that gets done only after a test fit. If it won't fit, I'll put them back on ebay - and perhaps I'll get the $60 I paid for them back.
 
Flowtech is owned by Holley. Here is one review I read online about their headers.
Reviewed by: Adam
Year: 1988
Model: Mustang GT
Price Paid: $0
Summary:
I am a profesional mechanic and have installed many sets of headers, these are the absolute worst I have ever seen. They are poorly made, the paint was rubbed off right out of the box, had to sand, repaint and heat cure. Also they fit very poorly, welds are terrible, pipe fitment is all off, leaked at collector connection. Had to remove from car and extensivily modify to get them to seal properly.

Strengths:
None, should have spent more money to buy a better set.

Weaknesses:
To many to list

Similar Products Used:
Hedman, Doug Thorely, Hooker, BBK, etc.


This was enough to make me look elsewhere.
 
Looks like I'll be selling them then lol. Like I said they are on my other block, which I plan to build up a little.

Anyways, I figured I'd ask first, because I don't like my Macs, and I had these laying around.

What are good headers anyways? I never bought a pair before, my Macs were given to me, and of course the Flowtechs were on my notch's old motor. My friend has FMS P headers for his GT-40P's and I like how they look as far as quality goes, and the paint on his looks like it's really holding up.
 
BlackFox5.0 said:
Looks like I'll be selling them then lol. Like I said they are on my other block, which I plan to build up a little.

Anyways, I figured I'd ask first, because I don't like my Macs, and I had these laying around.

What are good headers anyways? I never bought a pair before, my Macs were given to me, and of course the Flowtechs were on my notch's old motor. My friend has FMS P headers for his GT-40P's and I like how they look as far as quality goes, and the paint on his looks like it's really holding up.
The FRPP shorties are very nice. I think it would be hard to find a better shortie. 1 peice flange, 409 stainless, Jet Hot "Sterling" finish, lifetime warranty. :nice:
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If his FRPP shorties for the p heads are coated I doubt it's paint. It's likely ceramic coating like Sleeper's above. And it's the ONLY coating that will hold up on a header long term. The FRPP quality is some of the best around. And the units are made of stainless steel - so ceramic coating is the only option - if you choose to coat them. I recommend it.