???? Advice On Thread Sizes (for Line Convert) - The 1947 - Present Chevrolet & GMC Truck Message Board Network

PT'S 70 CST · 03-02-2004, 09:10 PM

I AM CONVERTING MY STOCK TRANSMISSION LINES TO STEEL BRAIDED HOSE. THE FITTING THAT GOES INTO THE TRANS IS 6-1/4 6 BEING THE LINE SIZE AND 1/4 BEING THE SIZE OF THE PIECE THAT SCREWS INTO THE TRANS. 1/4-18 PIPE TO BE EXACT. THE PROBLEM THAT I HAVE IS I NEED TO KNOW THE EXACT SIZE OF THE FACTORY PIECE THAT SCREWS INTO THE RADIATOR. IT IS NOT 1/4-18 PIPE AND I CANNOT FIND AN ADAPTOR FOR THIS, MY GUESS IS THAT IT IS 3/16 BECAUSE IT IS JUST A HAIR SMALLER THAN THE 1/4-18 AND I HAVE LOOKED EVERYWHERE FOR A ADAPTOR THAT WILL GO FROM 1/4 FEMALE TO A MALE FITTING THAT GOES INTO THE RADIATOR. THE ONLY OPTION I CAN THINK OF IS TO TAP MY RADIATOR COOLING LINE HOLES TO 1/4-18 PIPE TO FIT. ANY INPUT WOULD APPRETIATED.

THANKS PT

**kwmech** · 03-03-2004, 02:34 AM

The fitting that goes into the radiator is a tubing nut for 5/16 steel tube. I believe the thread size is 7/16-20 but it should be flared to seal correctly. Looked in my Russell catalog but could not find a part #. Maybe weatherhead.

gonebad2 · 03-03-2004, 03:02 AM

Hmmmm....could this be a newer radiator with metric threads? Usually you can get one for 5/16 tubing, inverted flare to 6-AN. I bought those at Summit. Aeroquip makes them. It's a pretty standard fitting. Quarter inch (original) tubing seems way undersized for a truck.

Blue Beard · 03-03-2004, 09:30 AM

Please turn the caps lock key off.

In computer terms, its like your yelling at someone......

Personally I find it harder to read.

Have you tried NAPA for the fitting? Thats where I got mine.

**JDL** · 03-03-2004, 10:39 AM

There is an adapter you get. Flare to AN. I have one.

03-02-2004, 09:10 PM	#1
PT'S 70 CST "GO DAWGS" Join Date: Oct 2003 Location: Batesburg, SC. 29006 Posts: 5,410	???? Advice On Thread Sizes (for Line Convert) I AM CONVERTING MY STOCK TRANSMISSION LINES TO STEEL BRAIDED HOSE. THE FITTING THAT GOES INTO THE TRANS IS 6-1/4 6 BEING THE LINE SIZE AND 1/4 BEING THE SIZE OF THE PIECE THAT SCREWS INTO THE TRANS. 1/4-18 PIPE TO BE EXACT. THE PROBLEM THAT I HAVE IS I NEED TO KNOW THE EXACT SIZE OF THE FACTORY PIECE THAT SCREWS INTO THE RADIATOR. IT IS NOT 1/4-18 PIPE AND I CANNOT FIND AN ADAPTOR FOR THIS, MY GUESS IS THAT IT IS 3/16 BECAUSE IT IS JUST A HAIR SMALLER THAN THE 1/4-18 AND I HAVE LOOKED EVERYWHERE FOR A ADAPTOR THAT WILL GO FROM 1/4 FEMALE TO A MALE FITTING THAT GOES INTO THE RADIATOR. THE ONLY OPTION I CAN THINK OF IS TO TAP MY RADIATOR COOLING LINE HOLES TO 1/4-18 PIPE TO FIT. ANY INPUT WOULD APPRETIATED. THANKS PT

03-03-2004, 03:02 AM	#3
gonebad2 Merciless Butcher Join Date: Oct 2003 Location: CC Nevada Posts: 1,447	Hmmmm....could this be a newer radiator with metric threads? Usually you can get one for 5/16 tubing, inverted flare to 6-AN. I bought those at Summit. Aeroquip makes them. It's a pretty standard fitting. Quarter inch (original) tubing seems way undersized for a truck. __________________ Your Bought And Sold....I Got Your Soul!

03-03-2004, 09:30 AM	#4
Blue Beard Registered User Join Date: Jan 2003 Location: Washington State Posts: 8,834	Please turn the caps lock key off. In computer terms, its like your yelling at someone...... Personally I find it harder to read. Have you tried NAPA for the fitting? Thats where I got mine. __________________ 1970 Chev CST 2003 Harley Fatboy 1975 Chevrolet Step Van 1956 Chev Bel Air 1977 Blazer 2WD For Sale $3000.00 1978 Blazer 2WD For Sale $7000.00 1978 Silverado 2005 Monte Carlo

03-03-2004, 10:39 AM	#5
JDL Senior Member Join Date: Sep 2000 Location: Agency IA. Posts: 1,841	There is an adapter you get. Flare to AN. I have one. __________________ 72 Chevy short step side with 454 air and tilt. 72 nova project car 63 chevy II drag car Agency Iowa

03-03-2004, 02:34 AM	#2
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,553	The fitting that goes into the radiator is a tubing nut for 5/16 steel tube. I believe the thread size is 7/16-20 but it should be flared to seal correctly. Looked in my Russell catalog but could not find a part #. Maybe weatherhead.



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