LT1 FUEL PUMPS

[Gregory G.]

The fuel pump for the '72 LT1 is stamped 40769.Is the fuel delivery and pressure,as well as its performance, the same as the '70 and '71 fuel pump stamped 40709?

[Joe L.]

Re: LT1 FUEL PUMPS

Greg-----

An AC type 40769 fuel pump is not the correct pump for a 1972 LT-1. The correct pump for a 1972 LT-1 is AC type 40709, just like the pump used for 1970-71 LT-1s. An AC type 40769 is a long cannister style pump used for 70-76 Corvette small blocks EXCEPT LT-1.

[Gregory G.]

Re: LT1 FUEL PUMPS

Joe,
The AC type 40769 is for the base motor 1970-72 and the '70 L46.I was incorrect.I should have referenced the 40709 to the 40956,which is on the 1972 LT1 per the JG.Are those fuel pumps the same in fuel delivery and performance?

Greg

[Terry M.]

Re: LT1 FUEL PUMPS

Greg,

I can't tell you about the fuel delivery specifications, but the visual difference - which is what the judges look for - is in the direction the fuel inlet pipe faces. 1970 and part, if not all, 1971 has the fuel inlet pointing towards the left rear wheel. The 1972 style has the fuel inlet facing the passenger side of the car. Both styles have the AC logo on the aluminum base of the pump, and are the short style as Joe and others have mentioned.
At onetime when one ordered the 40709 pump from Chevrolet the contents of the box were configured like the 40956 pump, so be cautious of NOS pumps.
As far as function is concerned, I know from experience that either pump will function fine on a 1970 LT1. One may need a slightly longer fuel inlet hose for one or the other installation, but then the inlet hose should be replaced periodically for safety reasons anyway.

[Gregory G.]

Re: LT1 FUEL PUMPS

Terry,
Thank you for the info.You explained the visual difference of each explicably.
Does the AC #40769 differ in configuration than the 40709 and the 40956?

[Joe L.]

Re: LT1 FUEL PUMPS

Greg-----

The AC 40769 is a completely different configuration than the 40709 and 40956. It is a "long cannister" style fuel pump. In other words, the large diameter, stamped steel, bottom section of the pump is much longer than the corresponding section of the 40709 or 40956. Also, the 40769 has provisions for a fuel return line; the 40709 and 40956 do not. By the way, if the car has a fuel return line, then it is NOT an original LT-1.

Terry is correct about the 40956 being used for 1972 LT-1s; I had forgotten about that change. However, the 40956 was never available from GM in SERVICE; the 40709 was the pump available in SERVICE for all 70-72 LT-1s. The 40956 may have been available through the Delco parts system and it may alternately have been provided in boxes labeled 40709, but it was never otherwise available in the GM parts system.

The differences between the 40709 and the 40956 are only as Terry described and relate to the angular relationship between the fuel inlet and fuel outlet fittings. The pump specifications are otherwise identical.

[Terry M.]

Re: LT1 FUEL PUMPS

“The 40956 may alternately have been provided in boxes labeled 40709"

I can’t give you the exact year I bought them - maybe late 1980s early 1990s - but I have [not for sale, just like Joe] two boxes with full Chevrolet part number, and 40709, with pumps configured like the 40956 in the box. I am certain I got them from the Chevroelt dealer, but who knows where he got them. I would have to look to be absolutely sure, but I believe the number stamped on the pumps is not 40956, and I am absolutely sure it is not stamped 40709. So at least for some time, while technically they were supplying the 40709, in reality they were supplying the 40956. However, when installed the number is next to invisible, so the configuration becomes the issue, and at that only in judging.
FWIIW: A reproduction of the 40709 is available from Goat Hill Classics, and perhaps other sources as well.

[Gregory G.]

Re: LT1 FUEL PUMPS

Several Chevrolet parts dealers stated, the only AC filter available for the base 350 and the HI Performance 350 is the 40769,which has a return line option,which I did not know.I have in the car the 40956,with the inlet facing the passenger side.I also called an AC Delco parts distributer and he stated, the 40709 is available for $30.00,highly unlikely from the info you provided.
The 40709 sounds like they only were installed on factory production cars.
I am leary about Goat Hills repro or their rebuilts on crimped style pumps.
Thank you and Joe for the info.

[Terry M.]

Re: LT1 FUEL PUMPS

Greg,
It is likely that the 40709 available from AC Delco is really configured like the 40956, but if they will order it and allow you to refuse it on inspection there is no harm in trying to find out what shows up.
I have had a Goat Hill reproduction on my car for probably five years with no problems. I am sure it was on through the Founders’ program, so it got a few miles on it. I believe they are the only game in town for a correctly configured 40709.

[Gregory G.]

Re: LT1 FUEL PUMPS

Terry,
I decided to order the 40709 fuel pump from the AC Delco distributor.I will take a shot at it for $30.00.I had to pay for it for them to place the order.If it is incorrect they will take it back for a 20% restocking fee.
I am pleased to hear you have good results with your Goat Hill 40709,based on that, I too will then purchase one from them.Paul Baker,from Goat Hill, said he has a rebuilt 40709 in stock.
I will let you know the part configuration and part number stamping of the new AC 40709 from the AC Delco distributor when it arrives.
I again thank you for your info.

[Terry M.]

Re: LT1 FUEL PUMPS

Just to be clear Greg, the 40709 I got from Paul is a reproduction. I have no experience with their rebuilds.

[Gregory G.]

Re: LT1 FUEL PUMPS

Terry,
Thank you. I will inquire about his reproduction 40709 instead.
Greg