Hey guys, im new here, but I thought i would chip in this bit of info. I bought a set of summit shorty headers for my '89 5.0 cause my manifolds were cracked and im too cheap to buy some good headers. First off, when i got them and took them out of the box they say FlowTech right on them. Now as i got ready to put them on, i decided to skip the cheap gaskets that came with them and get a set of Mr. Gasket Copperseal gaskets. So I started putting them on, they were a pain just like headers are supposed to be, but when i fired it up they were leaking like a busted water main. I kept tighting the bolts until they wouldnt tighten no more, and they still leaked. so off they come. I took a look at the gaskets, and in the corners of the ports there handnt been anything touching them. the flange on the headers is kind of oval instead of square. this is getting long so i will get it over with. I used the gaskets that came with the headers and no more leaks! so anyway, im happy now except the paint is already gone, oh well.

as for performance improvement? I dunno, but they sound a little different.

 

That sounds kinda screwy. I had a little more respect for Summit. Were the ports on the headers larger than your engine ports? I wonder if the flanges were flat in the begining. I also wonder why the flowtechs cost more than the summits if the summits are flowtechs.?*%

 

The ports on the headers were just about the same size as the ones on the stock manifolds, they just werent perfectly square. I was thinking maybe the Summit ones are flowtech 2nds? the paint on them (what little they had) is totaly gone and the welds were kinda ugly. at least they have 3/8" flanges, the dynomax headers I have on my other truck only have 1/4".

 

I hear ya on the Flow tech/Summit headers.When i had shorties on my truck i did the same thing you did.I ordered them because my manfold was cracked.When i got them i was like...... HUH Flowtech?
I also went with the copper seal gaskets.....$30 down the drain. They sucked...period! Leaks everywhere.
I finally went with Felpro HP gaskets....Good to go!

 

after taxes and everything i paid $50 for the stupid copper gaskets, now they are sitting in a bent heap on my bench I still have one cylinder that is leaking, so im going to go find a set of those fel pro gaskets.

 

Dave,
Also,keep an eye on the seal where the collector is ( where the header meets the exhaust pipe).They say you don't need a gasket there,but i went ahead and bought a doughnut shaped exhaust flange gasket.
It took alittle trial and error,but finally got it.

Good luck.

 

huh? on mine it has the built in round donut thing, just like the stock manifolds did.

 

Yes,that is what i'm talking about.Sometimes when your working with stock/aftermarket parts things don't line up so well.
Just keep an eye on that sealing area.If you don't have any leaks there don't touch it.

Good luck.
Jerry D

 

I dont want to start a war, but my summit truck headers on my old 92 302 fit perfectly and were leak free right out of the box. Just wanted to let you guys know that they arent all bad.
Good luck