1972 Dodge Polara 360/904 going to a 727 transmission conversion coolant lines questions.

72polarbear

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Just got my rebuilt 727 and 904 (that I may list for sale if anyone is interested) from the shop and now its time to prepare to plop it in. When I was removing the coolant lines I accidentally twisted one of the stubborn fittings but it was for the best since once of the previous owners swapped radiators and used hose to connect the lines that ended up being 3 inches short so better now than never. But I'd rather learn than have a shop make them so what do I need? What size line should I use and what tools for flanges and bending would you recommend or would a better alternative to buy braided hose and AN fittings and if so what do I need? Any help or suggestions are greatly appreciated.
 
If you are going to make your own hard lines the factory size is 5/16. If the ends of your original lines are not damaged cut them off and use them on the new lines. If it were me I would go with stainless steel lines. You will need a tubing cutter, a flaring tool and a hand tube bender, all are fairly inexpensive. For transmission lines you only need to do a single flare because the pressure is not that high compared to brake lines that require a double flare. If you are going to use hard lines from the trans to the radiator make sure you have some supports in between so the lines don’t move to much and break. The factory had supports that attached to the oil pan bolts. Not a hard job just take your time when doing the bends so you don’t kink them. By extra line and practice your flaring and bending before doing the real thing. Good luck.
 
Just got my rebuilt 727 and 904 (that I may list for sale if anyone is interested) from the shop and now its time to prepare to plop it in. When I was removing the coolant lines I accidentally twisted one of the stubborn fittings but it was for the best since once of the previous owners swapped radiators and used hose to connect the lines that ended up being 3 inches short so better now than never. But I'd rather learn than have a shop make them so what do I need? What size line should I use and what tools for flanges and bending would you recommend or would a better alternative to buy braided hose and AN fittings and if so what do I need? Any help or suggestions are greatly appreciated.
What I've done a couple times is buy lengths of premade 5/16 brake line at the local NAPA. They have ~4' sections and you'll probably need 4 of them, 2 for each line. This will have nice double flares at both ends. I cut the new line once I figure out where I need to and reuse the nuts from the old lines. Then to join the sections together, I use a compression union to join the sections together. You can also do this to repair the old line which I'd say will be cheaper and easier.

Of course you can always check with Inline Tube and buy the lines premade and ready to go. That's probably as cheap as making your own lines.
Transmission Cooler Lines
 
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wound up sourcing mine from Vans after the ones from Inline weren't close...think they sent out small block ones for my big block...put them in before dropping in the engine as that's the easy way, you really cant snake the right one through without bending the heck out of it if the engine's in place...fit great , looked great....then I installed my TTI engine pipes to my HP manifolds...they hit...had to rebend everything to clear...shoulda made my own
 
I bought Inline Tube's product, which works very nicely for our '68, just as they did for our '66, though with this new radiator, I've had to use a hose for the line from the transmission, owing to the coolant connector being in a slightly different location from the factory radiator I ran prior to it. Having used a tranny fluid cooler in conjunction with the old radiator made using a little hose necessary anyway, though most of my lines to that were still 5/16" steel also. If I were to use a cooler again, I would use hose. The new radiator does an excellent job of cooling everything.
 
There is a reason Mopar went to 3/8 and sometimes 1/2 inch o diesels ou need good flow no sharp bends and for those with OD trans go 1/2 put larger threads in trans case and larger fittings when you have it apart really helps those trust washers I converterd to straight cut gears best fluid is CITGO Quatrosyn next is ATF+4 OEM fluid is no longer available and obsolete anyway
Allison rated fluid is OK too stay from unsupported DEX III NEVER DEX VI
 
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