702 GMC V-12 powered '62 GMC 1-ton

[watahyahknow]

its kindah like that only it connects to the head itself 6 pipes going in the big log/ tank like thingy and from there the propper sized pipe to the pete stacks you might be able to make some sort of dampening material on the inside of the log but not mush it most likly will only stop the machinegun sound when you lift the trottle

[cayoterun]

Here's to ya, Mickey D. Thanks for the name. Balaur has 4 dragons/w three heads, each head firing one cylinder.

Exhaust manifolds/headers? There's plenty of room for about anything, except the left front head. We only have about 4" of clearance between head and steering sector. I'm sure it will take a homemade manifold of some kind.

[bb1979]

Cool project, I read that you sourced another piston from a junker motor but did any of the other leads eg Egge result in new pistons being able to be sourced.

I only ask because a hot rodder here in Australia is installing one of these beasts into a 32 Ford 3 window and his pistons are toast

[thirdstreettito]

Hmm, what about tranny?

[cayoterun]

For my use on this, I'd like to find a 5spd over manual from behind a 401 or 478 V-6 GMC truck and use as high a rear end ratio as possible. GMC used New Process, Clark, and Spicer, but so far, hard, hard to find. I do have a 5spd direct and 3spd aux that can be used, but wouldn't be as simple as an overdrive. There are other options such as a custom adapter for Automatic use, but very pricey. Final choice hasn't been made on this. Lot's of fitting and fabrication to do on the other stuff.
Thanks,
Cayoterun

[cayoterun]

Sorry, bb1979. I overlooked your question for piston sources. New pistons and internal parts are almost non-existant. There are places that will custom-build them. All parts new, or used are pretty pricey. When I was looking for pistons, a salvage yard told me he sold used pistons for $80. each, but didn't have any. I was never able to find any source with anything in stock. Good source for info and leads is www.gmcguy.org.

Exhaust manifold: This is what I finally came up with to get past the steering box. I'll probably need to wrap it with insulation as it still runs close to valve cover and steering box. I cut the stacks, connected them, then down & out. Steering box sits in front of pipe. Crude and rough, but hope it works. For now, will use stock manifolds on the other three.

Tranny: Another guy is working on an adapter for an T400 or 4l80E auto. It looks good so far, but not finished. An auto would sure simplify things.

[Hart_Rod]

Just spent over an hour reading your thread.........this is one of the coolest builds I've seen! Glad to see another Okie likes big trucks, .

[cayoterun]

Body mount position?

The belt line of the body--front clip, cab, and bed,---needs to run parallel, (level), with the frame? Is that right?

It's time to start mounting body mounts to frame, and wanted to be sure.
Thanks,
Cayoterun

[MonteSS454]

Why don't you just run stack behind the cab like a big rig?
Just collect all 4 header pipes into 2, run a muffler on each side under the cab then stacks behind the cab?

[cayoterun]

MonteSS454: I like the idea of stacks behind cab, but having a 60gal propane tank mounted on bed in that area, holding indirect heat away from it would be wise. By dumping exhaust underneath would make the safety inspectors alot happier, whether the stacks would pose a safety threat or not.

Damien: I don't know if a V8 header would match. There are headers made for Jimmy V-6, but since this is mounted in a different frame (F--d), headers would have to be custom, so we have ended up with this homemade set-up 'til we see how everything else comes together.

Progress: Radiator is mounted independent of front clip on its own frame crossmember. It's a 5 row tube industrial radiator.
Front clip can be removed by pulling about 8 bolts, and truck will still run and could be driven. Probably no hood to start with. Cab can be pulled by about the same # of bolts, and a few controls and wires. A bunch of improvements could/will be made later.
Tranny question still undecided, but hoping to use a T400 auto tranny.
I ask OHP about front fenders. They think we could run w/o fenders and front clip as long as we have the required lights in front. They couldn't find any statutes that specified certain requirments for FRONT fenders in Okla. REAR fenders/mudflaps, yes. Note: Important body working tool in floor. (trusty sawzall).

Thanks for all the suggestions. There are bits & pieces of any/all used in this, so let's keep thinking outside-the-box.
Cayoterun

[Damien]

Does the V6 share exhaust ports with a V8 that headers could be gotten for such as a big block chevy? If so, one tube could be cut out.

[HotRodYJ]

Seriousley cool build! I've not taken the time to read everything but the one thing I think would deserve the extra effort is custom headers. You can buy header kits from Summit and Jegs to build your own. Probably have to cut your own custom flanges to bolt to the block, but other than that it's just bits of bent tubing you match up and weld to whatever fits your application. I'd hate to see such an awesome build go by without a good looking header to match the rest of the project. JMO.

[watahyahknow]

i dont know if hey make headers for the V6 version of that engine but if they do you could use two and connect two into one pipe or use 4 mufflers

[HotRodYJ]

How about more of a traditional HotRod header with rod tube similar to this. Still be pretty easy to make yourself, but a much cleaner look.

[cayoterun]

Cab will be removed next. Th400 tranny & adapters should be ready to fit soon.
Pic#1 shows the close clearance we have between manifold and steering sector. Less than 4" from head to sector. Can't go down or the header pipe would have more crooks than an Arkansas backroad. (I'm a natural born Arkie). Hotrodyj, I agree that some custom headers would look much better, and are on the dream list. There are headers available for V-6s, but no room.
whatahyahknow, I thinking now to use flexpipe from what we have now to two glass pac mufflers mounted under the cab on each side, outside of the frame, then pipe back tipped out in front of the rear tires.
Pic#2 shows one good thing. Brake booster and master cylinder will be an easy graft from the F---, so booster, master, proportioning valve and all will match same donor truck.
I was glad the header pic was posted. It also let me see someone else used small u-joints and shaft for steering. I can get truck pto shaft locally, and it's heavy built. I think I'll only need two u-joints, and will use a square shaft & slip joint to absorb frame flex.
Pic#4 is where I'm at with extended clip. It's only a fake hull. Sure would be nice to have a flip clip like road trucks, but another dream list item for now.
What do ya'll think?
It's been 1 yr on 9-11 since we drug "Balaur" out of the barn and started this. I won't use the word "celebrate" as I can't think of anything to celebrate on that day.
Thanks
Cayoterun

[Storm Chaser]

I won't use the word "celebrate" as I can't think of anything to celebrate on that day.

Sure, you can use the word "celebrate" if you want. In our house, 9-11 is treated like a holiday. We watch the movie "World Trade Center" every year and whatever special might be on tv. Then we have dinner and remember the police and firefighters who gave their lives and honor those that still do every day. We honor those people who went to work just as they always did, but lost their lives. They were and still are the spirit that makes America stand out in the world. They died doing what makes this America- freely going about ther lives- going to work to make our economy and country run while making a better life for themselves. Just like the troops (who we also honor on this day), they died Americans- Americans doing what makes this America. You don't have to celebrate the attack or the fact that people died, but it's perfectly OK to celebrate their lives, the loved ones they left behind, and the fact that they didn't back down even in the face of death.

Yes, 9-11 was a tragic event, deserving of remembrance, honor, prayers, and even a celebration of sorts- celebration of American spirit.

You can do as I did, and dedicate your build to the victims of 9-11 and to the troops defending the very freedom the terrorists don't want us to have.

[sutton82]

I say make it look like this: http://www.hotrod.com/featuredvehicl...evy/index.html

Just kidding. This is an awesome project.

[special-K]

I`m enjoying your build.I can`t wait to see how the exhaust gets done.
Here`s something for fun:

[cayoterun]

Sutton82: Thanks for the Blastolene link. Most details I'd seen.

Special-K: There is/was? a one owner truck like that not far from here in Tx. Had to really slap hands to keep from buying. It needed to be restored, but a great foundation.
It was parked beside a big shop a few years back. Tornado came thru, destroyed the shop, but two broken windows were the only damage to the truck.

My project is kinda' on hold. Waiting on one more adapter to be machined. Trying to use a TH400 tranny. Once we get a tranny mated, then maybe we can start making faster progress. When it's mated up, then try to put faster gears in rearend so we can to try to reach inter-state speeds or above. The exhausts and the rest will all be pretty crude in the beginning. Just getting it to move under it's own power will be a major milestone for me.
I know this truck will never be as nice those in pics. Thanks for sending them.
Cayoterun

[Damien]

I don't know if anyone has run across this site. It looks usefull.
http://www.transmissionadapters.com/...%20&%20V12.htm
This one too.
http://http://6066gmcguy.org/TwinSix.htm

[cayoterun]

Thanks, Damien, A friend took a little different approach on our adapters. We had considered using those. Pics later.

I'm thinking that when we get the T400 mated to the motor, next week I hope, I'll try using a Spicer 3spd auxillary turned backwards. (Low would become high) Whether that will work is a debate within itself, but I'll never know 'til I try it.

Question? Would a shift kit enable me to hold the T400 in ANY GEAR, regardless of engine rpm? Preferably 3rd gear.

Reason: I need to hold the output shaft of the tranny at constant speed relative to engine rpm to shift the aux while moving since I won't have a clutch.
Old timers would say, "feelin' it in gear".

Hope this is clearer than mud.
Thanks,
Cayoterun

[Hart_Rod]

You can put a manual valve body in the tranny that will allow put it in a gear and it will remain there until you change it to another one. Good luck.

[cayoterun]

What are they called, where do you buy them, and does the tranny have to be removed to install them?
Thanks,
Cayoterun

[Hart_Rod]

Originally Posted by cayoterun

What are they called, where do you buy them, and does the tranny have to be removed to install them?
Thanks,
Cayoterun

Here ya go....

http://tciauto.com/Products/Instruct...21100_inst.htm

http://books.google.com/books?id=KKP...um=7&ct=result

http://www.hughesperformance.com/pdfs/HP2211.pdf

[locomotive breath]

Be careful using a full manual valve body, they are primarily for racing and shift very hard. You should be able to float the aux. trans. in and out just using the acc. pedal. I would probably try it first with the stock valve body and only go to the manual valve body if needed. There are two main ways to go about installing a manual valve body both of which require droping the pan and valve body assy. The kit types are cheaper and normally retain the stock forward shifter pattern (PRN321), while the complete valve bodies are often use reverse pattern shifters (PRN123)