Hi guys,
I've been getting some great info, and parts from this site. Great resource, so thank you to everyone for their input on my questions and parts requests.

I am in need of a gas tank for my '70 442 Convertible. Has TH400 trans but came really stripped out, so I am needing to replace a lot. There seems to be couple of setups for fuel delivery/return. One tank shows up, but sending untis are different. Can anyone help me understand if my car should be set up with a single sending unit or a sending and return line on my car? Any other details to look for here is greatly appreciated!
-Ryan

 

Someone else may have painful specifics, but I believe that in 1970, all GM cars had a single line except for California, which had the returns.
In subsequent years, return lines were included on more and more cars. I think all of them had them by '72 or '73.

- Eric

 

...and I was under the impression that all the high performance engines had return lines and, therefore, all 442s had return lines. My '68 4-4-2 is a Lansing car that was shipped initially to Washington State and it has a return line.

Randy C.

 

Now, that could be.

My direct 1970 A-body fuel line experience extends to my very original (and rusty) '70 Chevelle LS6, which has, and has had for the past 30-odd years that I've owned it, a single line, with no return.

I wonder why Olds would be different.

Maybe it's a West Coast thing?

- Eric

 

Randy would be correct. Don't confuse the fuel return line coming from the pump with the vapor line that goes to the vent ports on the tank. The difference between the single and two port sending units is the two port unit is for fuel return. The whole purpose of fuel return is to recirculate the hot underhood fuel to prevent percolation. It was used on all A/C cars and on all high performance cars, so a 442 should have fuel return. Does the fuel pump have two ports (one in and one out) or three (one in, two out)? A fuel return system would have three.

The evap line to the vapor canister was yet another line to the gas tank, but would not have run to the sending unit. This was used on Calif cars in 1970 and all models in 1971.

 

Car wasn't a CA car. The car was completely apart mechanically and I need to get a new fuel pump as well with the fuel sending unit and gas tank. Just wondering if I should be getting a two port to be correct for '70 non-CA car and if I need to be on the lookout for a different setup of gastank as well.

 

And again, ALL A/C and high perf cars got the fuel return line. CA cars got an ADDITIONAL vapor line on top of that.

 

Thanks for the confirmation.

 

Oh come on, Eric,you're disappointing me!
It's these little things that make Oldsmobiles better (and more expensive when new) than Chevies.
While the Olds owner rockets away with the A/C on, the Chevy owner is left in the dust with a vapor lock problem.

 

Ryan
your car has a 3/8 fuel line and a 1/4 vapor return

 

Well, I think it's just weird - hard to follow GM's logic sometimes.

No A/C allowed in the LS6 cars.
Wish I'd have known in 1980 that a bench seat, no A/C, and no power steering were going to be valuable features, 'cause I wouldn't have "improved" them all .

- Eric

 

I just ordered a Fuel tank for my 69 and got it at Rock Auto it lists for your car several tanks with 1,2 and 3 vents I will paste the listing these are Spectra Premium tanks made in Canada just got mine and looks great

1970 OLDSMOBILE 442 5.7L 350cid V8 : Fuel/Air : Fuel Tank WikiPriceSPECTRA PREMIUM Part # GM34Q Rebate/Promotion Available! See Promotions & Rebates Page for Details.
Exc. Station Wagon; w/o E.E.C.; w/ 2 Vents; w/ Filler Neck; (Tank Only - Does Not Include Fuel Pump);Lock Ring Kit Included
$112.79Add to Cart SPECTRA PREMIUM Part # GM34S Rebate/Promotion Available! See Promotions & Rebates Page for Details.
Exc. Station Wagon; w/o E.E.C.; w/ 1 Vent; w/ Filler Neck; (Tank Only - Does Not Include Fuel Pump);Lock Ring Kit Included (Only 2 Remaining)
- Stocked in outlying warehouse--shipping delayed up to 1 business day$130.79Add to Cart SPECTRA PREMIUM Part # GM34R Rebate/Promotion Available! See Promotions & Rebates Page for Details.
Exc. Station Wagon; w/ E.E.C.; w/ 3 Vents; w/ Filler Neck; (Tank Only - Does Not Include Fuel Pump);Lock Ring Kit Included (Only 2 Remaining)
$143.89Add to Cart SPECTRA PREMIUM Part # GM34QFI Fuel Tank Assembly (Rebate/Promotion Available! See Promotions & Rebates Page for Details.)
Exc. Station Wagon; w/o Evaporation Emissions Control; w/ 2 Vents; (Includes In-Tank Stock Capacity Fuel Pump); Use When Replacing Stock Engine w/ Late Model Engine w/ Fuel Injection; Lock Ring Kit Included (Only 2 Remaining)