Did a/c cars have a return line on the fuel system?

 

All the ones I have ever worked on did, yes.

 

The reason I ask is i have one and it dont show any signs of ever having a return line.

 

I bought a 1970 supreme a few months back , and my car is air, and I don't have return line also!

 

I've got a 67 Cutlass Supreme Convertible with the 330. It's got A/C and no return fuel line.

 

Not all of them. I have a 1971 Cutlass parts car with a 350 4bbl A/C and it does not have fuel return.

 

Here's some more detail. Answer = it varies

 

The OP has a 1970 model, so I assume he's asking about that particular model year. Pretty much all BBO cars with A/C got fuel return. All high perf cars also got fuel return. SBO cars (other than W-31s), not so much.

 

I have a 70 Cutlass S two door post with factory ac. Originally a 350 2 barrel car and yes it has a return line. I had to go look.

Live and learn.

 

So say you have a 350 a/c car and you put a 455 in it t you should add a return line?

 

I wonder about the specs of the fuel pumps in terms of volumetric flow and pressure and if the return-line-plumbed pumps were stronger. As I recall, the Rochester carbs could only take 7 psi at the needle before overwhelming the valve.

 

The key word on this subject is "varies". While accurate for 1967, in 1965 & 1966 the 400 cu.in. cars did not get the return line unless they had A/C.

 

The 1970 CSM shows 5-6 PSI (or 5-1/2 to 6-1/2 PSI) for the V-8 and 4-5 PSI for the L6. The reference to the return line says that it must be plugged when checking pressure. It also says that the pumps for the cars without the return line have an internal bleed valve. While there is no volume specification, there is a 15 in. (min.) vacuum specification for the suction side of the pump.