4L65E in a 68 FS C10
 

I just put a new Wizard dual pass rad in my 68 C10. I had an issue with a fitting on the old rad and had to install an auxiliery cooler for a while. I'm planning on replacing my cooler lines to the new rad and need to know what everyone is using. I'm using the copper/nickel stuff but what size? 5/16" or 3/8".
Thanks

Re: 4L65E in a 68 FS C10
 

The only thing I can tell you is that the original transmission coolant lines are 5/16". I'm not sure what size fittings the 4L65E or your new radiator use....

The Nicopp tubing is nice stuff. Easy to bend and won't rust. I use it for everything.
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Re: 4L65E in a 68 FS C10
 

LockDoc
Thanks for the reply. I was planning on using the GM push in type fittings on the rad but they all seem to be 3/8". If I can get a push in fitting on the transmission side I might go with 3/8" line. Problem is I don't know if the thread on a 4L65 is metric or standard. I don't think I'll be able to find a push in fitting with metric threads and standard 3/8" line size?
Jim