350 Vortec headers

[lcfman]

I want to buy a set of long tube headers for my 1977 C20. It will have a Vortec 383 so I will need headers for that engine. Anyone have suggestions or experience for this application? Will any small block header fit the early heads and the Vortec heads? Comments welcome.

 

[Kyle Childress]

vortec heads are no different than standard heads when it comes to header selection, the only difference in the two would be intake bolt holes and valve cover bolt holes. Standard Gm heads will have 6 bolt holes for the intake at an angle. Vortec will only have 4, two at the front and two at the back, and these will be vertical straight up and down. The valve covers on a vortec will be center bolt style, with 4 straight down the middle, older GM will have perimeter style bolt pattern and there will be 4. Not there are other center bolt heads, such as TBI heads and fastburn heads, but those are different balls of wax all together.

The only time you will see a difference in GM cylinder heads regarding headers is if they are the "fastburn" or zz4 heads, these will have angled plugs and are a bitch to find headers for. There are also some aftermarket heads that have equal exhaust port spacing like a big block/LS motor but I cant remember what those are called.

 

[Charlie]

 

[lcfman]

Thanks for the reply. Anyone got any recommendations for headers that fit good and are good for towing performance.

 

[shiftpro]

Well you want long tube headers so you're on the right track.
Which ever brand you select (sorry I can't recommend one over the other, as I've seen the same model # fit one truck and bring drama to others)
be prepared to 'blue print' the stinkers. Ball peen hammer is your friend. make sure there is enough room around the bolt holes to get a wrench in there,
and also verify that the port openings in the mounting flange are not smaller creating a step.
If you want to get your headers coated with ceramic or whatever, get them fitted firsthand.
You can actually dent headers in a lot (for clearance) and not suffer power loss.

 

[CiscoKid]

I have the Vortec engine in my truck too. Temporarily used the stock exhaust manifolds from original engine until purchased headers. I went with the cheap Jegs $99 headers on sale. Two cans of paint stripper and temp paint came off easily. Repainted with exhaust paint. Fitment was great and installed easily - no hammering required to install spark plugs. Holding up well. I would buy these again. Make sure to strip temp paint and use multiple coats of hight temp exhaust paint if you want them to last.

 

[MikeB]

Vortec heads (at least the current GM aftermarket version) have exhaust ports that are raised relative to the header bolt holes. I have found that most headers and gaskets tend to cover the top .125" to .150" of the ports, which is exactly where exhaust flow is the most intense.

These are the brand new GM Vortec "062" heads I used a few years ago,. You can see how much the ports are raised above the horizontal centerline of the bolt holes. Gaskets in picture are old school Fel Pro metal to show the offset relative to traditional heads. I ended up using Patriot headers along with 1.5" round port gaskets by Mr. Gasket. I still had to take a little meat off the top of the gasket port holes and some of the header ports. Thankfully there was enough flat mating surface on the headers and gaskets to ensure there were no leaks. Wish I would have taken pictures of the heads with the Mr Gasket gaskets.

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I can't recommend the Patriot headers because the front tube on the passenger side hit my hard lines (brake, fuel, vent, and return). I had to remove the fuel pump and motor mount bracket to bend the lines out of the way. Patriot (Pertronix) pretty much ignored my situation and actually suggested I move the engine a little to the other side! I think they were designed for 67-72, but the geniuses at Pertronix decided they were close enough for square bodies. I'm done with Pertronix/Patriot/Doug's forever!

I have since learned that Hooker has a relatively new P/N header that is designed for our trucks with Vortec heads. Check them out. The Hooker guy I spoke with was one of two guys at header companies (the other was a Sanderson distributor) who were aware of the Vortec port issue. The other guys are just cruising along blind and dumb!

Ah, just found the picture below. Fel Pro gasket for 96-up 5.7 liter Vortec engine. I used them with some Dorman cast Iron exhaust manifolds that I had to hog out at the top, even though they were listed for 96-up 5.7L engines.

All that said, I have seen pictures of earlier production Vortec heads that did not have the raised ports, but just about every used pair you find will have hairline cracks somewhere.

Whew!

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[MikeB]

Almost forgot this: Vortec head spark plug holes are located closer the exhaust port holes than on traditional heads. With some headers this means header tubes that turn down quickly can hit the plug(s) or plug boot(s). Maybe the small "ISO" style spark plugs will solve the problem, but I don't know for sure.

Bottom lines is Vortecs are a PITA. If I had a do-over I'd get some aftermarket aluminum heads that use traditional manifolds, headers, valve covers, gaskets, and bolts. And then there's the limited valve lift, and valve springs that work only with cam lobes that have very mild ramps, but that's another story.

 

[lcfman]

Thanks MikeB that is good information. I will get in touch with Hooker and get the part number.

 

[lcfman]

MikeB I just got off the phone with Hooker and they gave me part number 2452HKR. Is this the right part number?

 

[Frankenchevy]

I believe some exhaust ports were designed to hit a “step” at the top (or bottom?) where meeting the manifold to increase scavenging and velocity.

Something to look into.

 

[Kyle Childress]

MikeB I just got off the phone with Hooker and they gave me part number 2452HKR. Is this the right part number?

Yes those are the correct headers, I have ran those on both 062 casting vortec heads and a set of 882 heads, there were not fitment differences what so ever. I am currently running the 2452-1HKR on my truck, which are the ceramic coated version. I suggest getting the ceramic coated if you want them to hold up better, the black paint will be gone within the first 10min of driving. The ceramic is tougher and generally lasts longer, but it is NOT a rust preventative (though it does help). All headers that aren't stainless will rust, regardless of what someone will tell you. Here is a picture of them installed while I was doing the build on my truck. Also, do not break in a flat tappet cam on ceramic coated headers, it will ruing the ceramic an make them foggy, I suggest using a old set of headers or manifolds for the cam breaking then put on the new shiny ones.

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