Summit SUM-G9001 Headers, Mods needed?

At the suggestion of a couple people here and on the New England forum, I got the Summit Racing G9001 headers. Do they need any sort of mods before they're installed on a TBI car? I'm ready to send them out to get coated, but the shop suggests test fitting before they coat em, I don't want to sideline the wagon for 2-3 weeks if I can mod them without having to install them based on those who have done it previously.

According to Summit, they fit up to an 89. If they fit an 89, they should also fit a 91-96, because the engine compartment is the same. You have to put an O2 bung on the driver's side. Put it on the top or at least at 90 degrees so that it is always dry. Expect to make a patch cord for the O2 sensor. I put an extra wire clip on the top screw of the converter cover to guide the wire (I got it from an oil pan rail on a JY engine). You will have to reposition your oil pressure sensor to point toward the rear of the car (the wire will still fit). Another mod you will run into is the dip stick. The dip stick has to go between the headers and the head. You can use the original dipstick and bend it to the necessary shape. The person who transported my engine destroyed my original dipstick, and I ended up putting a shorty dipstick tube on it and had to bend it close to the block, and front a little to clear the wiper motor. With two bends, I had to make a corkscrew dip stick to go around the two bends on different planes. There is a bolt hole for mounting a support for the tube on the side of the block. You may be able to make a single bend, and turn the tube to face further front. If you look up the thread about my installation of shorty headers (not sure where it is anymore), it should require the same mods.

There are a lot of pros and cons to wrapping the headers, and I would recommend it to keep heat out of the engine compartment. The headers get much hotter than the original manifolds, and will melt a lot of plastic stuff. They also go very close to the oil pressure sender, brake lines, and the wiring behind the trans linkage pivot at the frame on the driver's side. A heat shield should be installed if you are not wrapping the headers. The plug boots are extremely close to the headers, and if you do not wrap the headers, you need some protective boots/covers for them, or they will melt.

You will also have to make a custom set of ignition wires, and add looms. There are bolt holes for the looms, but the ones I found required some modification to keep them out from under the header flange.

Stay away from header wrap. If you are worried about heat, get them coated. 4 years now with uncoated longtubes on an LT1 and a total of zero things have burned or melted.

Just dropped them off at the coating shop this morning. I just needed to confirm the headers didn't require mods. I'm ok with any adjustments that need to be made to the car. Thanks for the advice guys.   

You will also likely need a heated o2 sensor, I noticed on my C10 when I put longtubes it would go into open loop quite often and killed the fuel mileage. I believe the one to use is from a 95 S10 4.3L, it's a 4 wire. I used a new Honda sensor I had lying around and it works great.

Is dual exhaust necessary to run these headers, or can they be piped into a single exhaust to avoid doing all of the mods to go duals?

Viceroy454 wrote:

Is dual exhaust necessary to run these headers, or can they be piped into a single exhaust to avoid doing all of the mods to go duals?

I'm not sure. They exit around the transmission pan, you'd probably have to make the Y pipe behind the trans, but now you're almost halfway down the car. May as well just go true duals. There wasn't any super difficult mods needed. I'm running my stock cross member, my exhaust guy just tacked the new hangers in place on the DS, and slightly reroute the ABS cable in the rear. All I had to do after was put header wrap on the DS ota pipe to shield the gas tank

If you really want a single exhaust, you can get a dual in single one muffler. Went that route on my C10. 2.5" pipes off the headers into a dual in Magnaflow, Single 3in pipe out.

MalibuSSwagon wrote:

If you really want a single exhaust, you can get a dual in single one muffler. Went that route on my C10. 2.5" pipes off the headers into a dual in Magnaflow, Single 3in pipe out.

But considering how far back the muffler is on a wagon, you may as well just run duals then too.  Idk, just strikes me as odd to go thru all the hassle of a header and a custom exhaust only to run a single.

Cadet57 wrote:

MalibuSSwagon wrote:

If you really want a single exhaust, you can get a dual in single one muffler. Went that route on my C10. 2.5" pipes off the headers into a dual in Magnaflow, Single 3in pipe out.

But considering how far back the muffler is on a wagon, you may as well just run duals then too.  Idk, just strikes me as odd to go thru all the hassle of a header and a custom exhaust only to run a single.

Magnaflows are expensive, and I hate cheap mufflers. Therefore I only bought one muffler, but still have a nice free flowing exhaust.

However, there is much less clearance on the cars to run piping as opposed to the truck, So sticking to the factory layout is likely your best bet.

Before you send them out, lay a flat edge across the surface. On the lastt pair of headers I got from Summit, the mating surface was badly warped, giving me fits for sealing with the gaskets. I had to get them machined flat, then they finally sealed.

Dave

lakeffect wrote:

Before you send them out, lay a flat edge across the surface. On the lastt pair of headers I got from Summit, the mating surface was badly warped, giving me fits for sealing with the gaskets. I had to get them machined flat, then they finally sealed.

Dave

They've been in the car for almost two months. Once I retorqued the bolts, nice and quiet at the flange. Plus those Percy's aluminum gaskets seal like no ones business.

justin, i was talking to you at the fest about these headers. i think im gonna go ahead and order these. i bought a heated o2 sensor. i remember you saying they were pretty much bolt on. they install easier from under the car and you need to grind off the two little frame cross member thingys. was there anything else you had to do?

benn wrote:

justin, i was talking to you at the fest about these headers. i think im gonna go ahead and order these. i bought a heated o2 sensor. i remember you saying they were pretty much bolt on. they install easier from under the car and you need to grind off the two little frame cross member thingys. was there anything else you had to do?

Nope. Put the O2 bung in the top of the collector on the DS, cut the frame braces off the car and install. I used a three wire heated O2, out of a '94 C1500 Denso 2343005. This is the adapter harness I used. http://www.ebay.com/itm/370631184045?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT . Run the pink wire to the pink wire on your AIR pump, black ground to the DS firewall ground, and the stock O2 plug will have to be lengthened to reach the harness.

oof $29 is quite pricey for a bit of wire and a couple of weatherpacks connectors. Thats a third of the price of a weather pack kit with tool!

MalibuSSwagon wrote:

oof $29 is quite pricey for a bit of wire and a couple of weatherpacks connectors. Thats a third of the price of a weather pack kit with tool!

Maybe, but not knowing how to build one, plus having the correct O2 plug end on it was worth it to me.

Thanks Justin! Mines a 4 wire o2. I might try making my own harness. I'll take pics of the install for this thread.