Thread Size for TBI

[Madbomber88]

Does anyone know what the thread size is on the Throttle body for the fuel line and return fuel line?

I'm converting my 72 K20 to TBI and want to use Aeroquip's socketless tubing, but need to know what fittings to get, and they list them as NPT and AN. I know the threads are metric.

Thank you in advance.

 

[fortcollinsram]

supply line is a 16mm saginaw fitting and the return is a 14mm saginaw fitting. That is what is on the end of the factory TBI fuel lines that go into the adapter on the TB. I dont know what kinda of thread the actaul TB is threaded for. All I know is that they use teflon flat washers to seal

 

[southernspeed]

You can buy the proper fittings from turbocity. They accept a push on hose.

 

[Madbomber88]

Thank you, that's exactly what I needed.
Next and last question: the feed line is 3/8 and the return is 5/16. Is there anything wrong with replacing the 5/16 one with a 3/8? I can only get the tubing in -6 (3/8) size. What will this affect?

 

[southernspeed]

It'll be fine if you can get it to seal on a 5/16 fitting. Earls do a braided black hose that is 8.9mm i'd which is between 3/8 and 5/16, that's what I use.