Anyone want a good laugh while they answer my header/head question?

StreetDreamsGT

New Member
Mar 6, 2003
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New Jersey
Ok so for a lil while I was having trouble getting my bbk headers to mount to my 93 gt40 heads.....it hit me today, what if I had the heads installed backward? Sure enough, I go out checked out the heads grabbed a header n lined it up next to the opposite head, and it lines up fine...looks like I have the heads installed on the wrong side...sound possible?
 
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Naa, I know people that have installed heads backwards and the headers still fit. They found due to dyno results, they changed the sides the heads were on and gained about 150 horse. So there is something wrong with the headers or you could have the heads on backwards.
 
If they (heads) were directional they would be marked left hand or right hand or driver side or passenger side but I have never seen these markings on a SBF heads. Sounds like the flange on your headers is backwards but I don't think the flange is directional either only the tubes are?
 
I agree that it is not possible to install the heads backwards per se in that the intake and exhaust ports will be where they are supposed to be no matter what side they are installed on, but wouldnt it be possible to install the heads backwards in the sense that the emissions holes are to the front and the accessory holes are to the rear. Doesnt have an affect on this post, just wondering.
 
I had kinda figured the heads weren't side specific, but if the headers will fit on em only one way then I figure it's worth it just to switch the heads... I mean if they'll work either way but the headers only work if I have em on the one way then why not swap em over to save me the trouble of messing with the headers or buying new ones?
 
So, the bolt holes won't line up? Is that the problem?

I want to say that switching heads won't solve the problem either. A bolt hole only needs to be off fractions to not allow the bolt to pass through. It can be off so slightly, that you can get the bolt through and into the threads...but it won't actually thread in. But when you move things around a little, it gives you that extra fraction of a MM to thread the bolt in. Assuming you are just test fitting the header by attempting to bolt it on with the collector flange facing up and towards the engine.

If that is the case, when you swap heads you will run into the same problem. It isn't as much as the holes won't line up...it's more to do with the angle of the header itself. If that makes sense.

Are these used headers? If so, you might just want to have a machine shop resurface the headers, then they should line up. I had the same problem with used headers once before, I had them resurfaced and they bolted on with no problem. Headers tend to warp slightly.