C-6 Lines

[jf100]

I got a C-6 transmission out of a 1978 van. The transmission lines did not come with the transmission. Does anyone know what the thread size
is on that transmission line? So I can buy line and bend my own. Thanks for any information it will put me that much closer to having it up and running.

[sargentrs]

This says it's the correct fitting in the transmission for a large range of models including a 1978 E100. Pretty much hasn't changed since 1975-2013 according to the Dorman catalog. Available through your local parts store or online.
https://shop.advanceautoparts.com/p/dor ... 20230060-P

Replacement lines are also available for our trucks but I can't guarantee fit and routing. Would give you something to work with/modify that's probably close and not expensive. Stainless also available.
https://www.inlinetube.com/pages/produc ... 0179808896|

I twisted off my transmission lines at the radiator (5/16" tube) on my '74 Dodge Dart, but same applies to our trucks. I cut the ends off and added compression fittings to mate 3/8" MPT flared fittings. Then went to my local hydraulic hose shop (Parker Hannifin) and had some custom high pressure 3/8" reinforced hydraulic hoses made (about 12" long) with flared swivel ends. Only about $20 ea. Used matching connectors at the radiator. Makes installation from the front crossmember to the radiator simple, flexible and worry free.

[cep62]

You can use 5/16 steel line and bend them yourself.
I get the coated lines , they last longer in salty conditions.
If you don't have a flare tool you can use compression fittings.

If you're laying on your back doing this , I've found it easier to use two pieces and
bend from the trans and the radiator and connect them in the middle,instead of
wrestling one big piece of tubing.

[basketcase0302]

Another trick from a retired HVAC tech is to buy a roll of 3/8" soft copper tubing, (not real cheap but you'll more than likely use it around the house later on plumbing lines) / run the copper making all the bends easily to be used as a "template" / then bend your new steel line to match your copper tubing template. A cheap hand held tubing bender, (several are made that bends 3-4 different sizes of tubing) is a really big asset here as it will stop you from kinking the tubing, (a hard/costly mistake commonly done here) and well worth the $15-$25 spent on it.
Like Randy said above there are literally hundreds of different configurations of the lines versus different vehicle and engine and exhaust combinations and like CEP62 said above making them yourself will actually save you money while allowing you to put them exactly where they need to be, (off of exhaust header or piping / close enough to front framerail to clamp / out of the fans rotation).
You'll also need to buy a flare tool as the fittings will be a 5/16" inside flare like said above.
I got my 5/16" stainless steel line from Summit as they offer so...many different choices at a decent price.

https://www.summitracing.com/search?Sor ... l%20tubing