Need input on running trans cooler lines

[ZEKE68]

Next to the last problem I have to solve on my rebuild is running new transmission cooler lines. Planning on running an air cooler in parallel with the radiator cooler and teeing in the front to each. The reason I am running parallel is because the radiator cooler is 5/16" line and the transmission is supposed to be 3/8" and in parallel I will maintain the higher flow . Any ways I have been back and forth about where to run to run the lines, 1. up by the oil pan like the factory did it and having flex lines in the front, or 2. running down the frame rails and putting flex lines from the transmission over to the frame, in which case I will have to fab up a heat shield above the exhaust to protect the flex lines. Looking for some comments from experience to get me off the fence. Sorry for the long post.

[The Rocknrod]

They have heat sleeves you can use instead of building a heat shield, should you use flex hoses.
Also they have trans cooler to radiator adapter fittings that go from the pipe threads in the radiator to 3/8" tube inverted flare. Then go from radiator cooler to air cooler then back to trans. That is the most efficient way to cool the trans.

[Rufas]

I'm running stainless steel lines with stainless steel flex lines form Bowtie Overdrives on my GMC. These lines run parallel to the oil pan and then flex to the radiator. Bowtie makes these lines for the 200R, TH-350, TH-400, 700R4 and 4L60E.

These lines are very good quality and they actually fit without mods. I have the lines for the 700R4 on both my 1970 GMC and my 1967 Cutlass with a BBC. The lines on my Cutlass were installed in 2011 and haven't had any problems with them.

Bowtie Overdrive Trans Cooler lines

[ZEKE68]

Those are nice looking setups. Unfortunately I am running a 4L80E. I could use a set of lines for a 4L60e and add the 8" tube to the rearward inlet on the 4L80e but all of the sets of prebent cooler lines I have seen are 5/16" tubing. This transmission came stock with 3/8" cooler lines and I hate to reduce the oil flow from the stock level. It may not hurt it but I would always worry about it. How are things in Box Elder? I have been to the Rapid City area a few times and I love the place. They were all summer trips though so I don't know about the winters.

[davepl]

I'm no rocket surgeon but I'd think that if you ran them in parallel the fluid is going to take the path of least resistance the the higher resistance path will flow next to nothing at all. That's why I ran mine in series.

I can make arguments for both ways in series (before or after the factory cooler) but I have my doubts about parallel working well at all...

[Rufas]

Originally Posted by ZEKE68

Those are nice looking setups. Unfortunately I am running a 4L80E. I could use a set of lines for a 4L60e and add the 8" tube to the rearward inlet on the 4L80e but all of the sets of prebent cooler lines I have seen are 5/16" tubing. This transmission came stock with 3/8" cooler lines and I hate to reduce the oil flow from the stock level. It may not hurt it but I would always worry about it. How are things in Box Elder? I have been to the Rapid City area a few times and I love the place. They were all summer trips though so I don't know about the winters.

I'm pretty sure those are 3/8 lines. These lines are cut to fit for for needs with very drought couplers. I think I might over removed about a foot to get the lengthy I needed.

To make sure call Bowtie.