350/400 & 700R4 trans lines

[Slammed67]

Are the trans cooling lines for the 700R4 same size as those for a TH350/400? Are the connection sizes the same? In other words, if I bought a set of pre-bent lines for a TH350, would they hook up to my 700R4?

[breeh]

Good question. I would like to know also!

[Woody]

I havn't done it yet, but I asked this question a yr or so ago and was told they match up with very little bending needed near the tran. end. I would check the fitting and make sure the ones in the trans. aren't metric. My depend on year of 700R4...

[Slammed67]

Found this on a web site....

"......Every one of these General Motors vehicles are quite simple to change over to a TH-700R4 transmission. If the vehicle had a TH-350 or Aluminum Powerglide it’s simpler yet because the yoke on the drive shaft is the same 27 spline count therefore the drive shaft only needs to be shortened and balanced. Th-400's used a 32 spline yoke on the transmission end of the drive-shaft so that will have to be changed to the 27 spline yoke. Most conversions will require the cross member to be modified and relocated slightly, the original transmission cooling lines to be slightly reshaped and the TV cable system hooked up properly.

So I assume from that they very close to being the same in shape and have the same connection sizes.

[68 with 350 TPI]

Most of them fit with just bending the lines so that it hooks up at the right spot.

You may need to move the crossmember back a bit and you will need to get the driveshaft shortend/balanced.

The th350 has the same yoke so it will work but all others will need to be changed.

When you get a 700 out of a yard try and get the yoke that was attached to it if you had a manual or another auto.

[Slammed67]

Thanks. I already have the trans installed and the driveshaft connected. All I am needing now are the trans cooling lines. I was checking out some pre-bent stainless lines form Inline Tube, but they only sell stuff for stock applications. Therefore there was no part listed for a 700R4 in a 67-72. I e-mailed their customer support and there reply was that they'd probably fit but they couldn't tell me for sure. But it appears that the conenctions are the same, so I went ahead and ordered a set for a TH350. I'll let everyone know how they fit when I get them.

[Mixup]

I had a turbo 350 with stainless steel lines and when I went to the 700R4 they fit just fine. I had to do very little bending and I think it was only on 1 line. Its been awhile since I did it but it was no big deal.

['72 Cheyenne Super]

If you do use the stock (in the radiator) trans cooler, I would strongly suggest getting a trans temp gauge. 700R4's don't like heat, and if they run consistently above 160*, they'll cook. I had to use a separate Hayden cooler on mine (bypassing the radiator altogether) to bring the temp down to a reasonable level. Mine will now run at 150*-155* all day long.

[Doc Harrel]

Just bend your own. Autozone has steel fuel line and Ace Hardware has a nice selection of fittings. You can get a bender, cutter and flaring tool pretty cheap, and they are good to have for the copper lines that go inside your house. That way you can keep the lines out of the way and route them how you want them. Try to avoid unnecessary bends so you can get better flow.

[leddzepp]

The Truck Shop in Orange has pre bent transmission lines for TH350/400 trans as well as 700R4 transmissions.

[Doc Harrel]

If you run your own lines you might consider installing a remote trans filter inline on the return line from the radiator. If you live in a warmer climate, you could also install an auxillary cooler inline. And if you purchase the said tools you will have everything you need to do all of that.

[michael bustamante]

350 and 700 r4 trans cooler lines have the same thread pattern, I just did this the other night and only had to bend the upper tranny line a little bit