86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Guys.
I need your expertise. I have an 86 C10 2wd Single Cab Short bed. I am in the process of installing a 6.0 and 6L90E, not an 80E... Everyone seems to think I make a mistake by saying 90E... But it's a 90. Anyways, my question is, does anyone know of any Long Tube Headers that I can purchase that will fit without me having to notch the frame on my truck, or heat and bend the headers. You know "Direct fit bolt in and go" long tube. I have searched high and low, read almost everything there is to read on this forum, and haven't been able to find the exact answer to my question/application. I keep seeing everyone has a 4L this or that trans and what they're using for headers, but not much on the 6L Trans. I have contacted several header manufacturers and they all say that they have only test fit their headers on swaps with the 4L series trans. Getting pretty frustrated at this point :banghead:. Any and all help on this will be greatly appreciated. Also, I have a set of the dirty dingo slider mounts if that makes a difference or not in the combination of parts swapping for fitment of the headers. Part#'s and a website link to order from would be the bees knees.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Any header that will install with a 4L80 will also clear a 6L80 or 6L90 transmission due to the pointed ears on the bellhousing of the 4L80 creating the worst-case scenario for header fitment in an LS swap.

The only variable you need to consider that will determine the ultimate fitment of the headers in your truck besides that is the inclination angle you install your engine/trans at.

For example, If the headers were designed to be installed with the engine inclination angle set to 4 degrees and you install your combination at a more severe angle to allow the taller case height of the 6L90 trans to clear your floor without cutting it, then the collectors will be angled more towards the ground then they were intended to be.

The Hooker 73-87 GM truck LS swap headers will fit your truck and transmission, but their bend geometry is only compatible with the matching Hooker engine mounting brackets.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Thanks Todd. I bought you guys trans cross member and cantilever bracket all ready to mount the trans with. So your saying I need the motor mounts too, and a set of you guys Long tubes will fit in my truck with maybe having to knock off some ears on the side of my trans possibly? I got a grinder and know how to use it.. LOL. I ain't skeered of grinding off some ears if that's all the modifications I need to do to run long tubes.
I have This:
12646HKR
12645HKR
I need this?
12621HKR
2334-1HKR
70501414-RHKR

Thanks for all the help Todd!

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Yes, you would have to use the Hooker 12621HKR engine brackets to use the Hooker headers. You won't have to do any grinding to your bellhousing as the headers are designed to clear the protruding ears on the 4L80 bellhousing, which is smaller than the 6L80/6L90 bellhousings.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Awesome!! Thank you so much for the information. Hopefully this will help someone else in the future. And the 70501414-RHKR are designed to fit those headers along with 42107HKR adapter pipes?

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Yes, you've got it straight. Keep in mind that the horizontal alignment of the headers to the exhaust system is dependent on the engine inclination angle provided by the Hooker transmission crossmember for any of the transmissions covered under the application. Since your 6L90 is a custom application, you may end up with an angular discrepancy at the header-to-exhaust system connection if your engine inclination angle is different than what was arrived at for the other transmissions.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Well I went on and bought the ceramic long tubes and engine mounts. I had the adapter pipes and full exhaust system sitting in the cart, but decided to just go on and get the headers and engine mounts for now since we have determined that they will fit. Once I get everything mocked up in place, I'll order the rest, that way if I have any fitment issues due to some unforseen angle issue from the trans and cross member, I'll haul the truck to Kentucky and we can all see what the issue is..Lol. Just kidding. Though I would if you guys wanted to do some investigating with my combination. I'll just pack everything up and return ship the rest of the exhaust to y'all. I think we got everything sorted out. That was pretty easy. Thanks again Todd.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

No problem, it sounds like you are on your way. There's been no mention of expanding the application to include that transmission, but I will use your experience with the set-up as a gauge to decide if it's something worth mentioning to the product management team. I have a feeling you're going to need to do a little floor massaging above the trans to get everything to clear and end up with optimized U-joint working angles. PM me if you get stuck on anything and I'll be glad to help you out.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

What kind of kick backs are we talking bout here if you guys do use my R&D?? LOL. Just kidding. Thanks for offering to lend me your expertise. I hope I don't have to mod the floor to accept the trans. But if I do, I know where plenty of road signs are LOL. Hopefully the management team does foresee a need for parts for these combinations. I know there are plenty of donors out there of this particular combo.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

The two disadvantages to using a 6L80 or 6L90 in a Squarebody swap are both related to fitment; they have the tallest rear height of any GM automatic and their pan hangs down the lowest, so installation is more troublesome than other transmissions and they don't lend themselves for use on lowered trucks.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Thanks for that bit of knowledge. That's pretty handy info. My truck is as low as I want it to go. So hopefully the trans oil pan shouldn't be an issue. Though the floor pan may present itself as a bit of a challenge. If it does though, I guess my first ever welding experiece with the mig machine I bought a week ago is going to be my first project. Gotta start somewhere huh. Might as well be on a square. :)

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Here's some update pics of what we had to do using the hooker engine mounts, long tube headers, and the cross member. Totally had to massage the floor. But a high hump tunnel truck would probably clear the 6L90 trans no problem. Didn't use the cantilever bracket on the trans and cross member..the angle was off.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Two more since I can only upload 5 at a time

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

As a helpful observation to you, the way you have the crossmember installed is backwards from its intended design geometry. The side with the bolt-on foot goes on the passenger side frame rail, which positions the plane of the center beam with its angle sloping down towards the rearend to correspond with the down-angle of the engine. The headers seem to fit your trans well.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Having it installed backwards, would that make much of a difference since the angles are correct from the tail shaft to the diff?
Headers fit great!!

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

You will have to recheck your angles and possibly shim the trans mount by some amount, but the mount face will be far more parallel to the surface of the cross beam. The mating surfaces of the mount and the cross beam are not on the same plane the way you have it installed now.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Thanks Todd. We'll get to checking, and probably turning it around.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

I'm sure you'll be much happier with it in the intended orientation and find it worth the effort.

Re: 86 C10 2wd 6.0 6L90E (Long Tube Header Advise)
 

Thanks for the heads up on our mistake. I'm sure I will be too