Exhaust Manifold Questions
 

okay, so i got a 1999 F150 with the 5.4, and i have the infamous manifold exhaust leak and its getting worse so i think its time for replacements.

My question is:
are these worth buying or are they just more work (Harder to work around?) and i should stick with stock replacements? these are just on a crazy sale currently
https://www.protuninglab.com/hds-f15...QaApEtEALw_wcB

Can't help you with what they're like to work with but you can get these on ebay for around $80.

if its just the gaskets are bad i would buy the gaskets only but if you actually have holes in your manifold i would give that set a try if it looks close enough to oem i cant say if those would be easy to work on even the stock manifolds youll have to go at a bunch of different angles to get them out obviously remove the inner wheel well covers. hopefully you dont have rusted bolts and studs ive had an oil leak on my engine so theres literally no rust on the studs. i know doorman makes replacement manifolds but i heard and have seen they are crap and crack. id give those a shot or some genuine manifolds

I can tell you an experience with dorman manifolds. Years ago we had a 2001 f150 5.4 brought my uncles shop for a cracked exhaust manifold. We replaced it with a dorman manifold. Truck ran and sounded good so we sent it back to owner. 2 years later it comes back with a crack worse than it was 2 years before on the original. Dorman manifolds are not made very good

That's because the root of the problem wasn't fixed. The trans mount, hanger plate, fixed or replaced (straightened and welded if cracked) and most of all, exhaust Y damper updated. That's why they break, common problem with these trucks.

Yea, you can use those. No performance gains, nothing wrong with using them though. I would use better studs/nuts or bolts, if it were me. Replace the trans mount at the same time, they are cheap...around 30 bucks. make sure the damper is still there as well. Otherwise all drive-line vibration (metal to metal) and down pressure will compromise the install in the near future.

Okay..thanks for all the input..so is it even worth getting those headers?? Or should i just get replacement OEM manifolds for cheaper? Like i thought maybe for that price if they helped sound and performance a little itd be a nice bonus...but if they wont do anything...

If the OEM manifolds are cheaper, that's what i'd use, because you aren't gaining anything with the headers.

Are the trans mounts hydro filled? I assume they shear like the mounts on the earlier 4R70W cars? Is there a solid rubber option available?

i patched my exhaust manifold gasket failure with jb weld and it lasted longer than it needed to and was difficult to remove when i got around to replacing the manifold - it worked! - it was cheap! - the inspection station didn't know it was there because it wasn't making noise !!!