[patox]

Hi there, trying to find a decent stock fuel pump for my GTO's.
The 66 has a 66 389 on it, and the 69 has a 70 400.

I heard all pumps are the same, but both rockauto and summit are kind of picky with the options, rockauto showed one carter pump as "one year only" for 66, and summit differences between 66-67 and all the rest of the years, as well as 326, 389, 421, vs 400 and 455.

Both engines are stock, no need for massive flow nor want to use regulators if possible, looking for some carter, AC or Airtex, nothing fancy like Rob´s stuff.

Can I use the 70 400cid pump on the 66 389cid for a while?
Witch one will you recommend for each one?

Thanks!

[1968GTO421]

I'll let others more familiar with your car chime in and give you more specific info. I will say that Summit is correct with the different listings for mechanical fuel pumps for Pontiacs as there were differences between them. I am pretty sure they will all fit on your cars as the gasket shape is universal are the bolt locations and the arm length between 1966 and 1970. The differences lie with the number of fittings on the pump, one goes to the carb, one pulls fuel from the tank and there can be others for fuel return, vapor control, etc. Depends on how the original pump on your car was set up.

[steve25]

Look at the sponsors of this web site Ames performance catalog.

Yes, the pump for a 70 400 will work but for any possible issues with output line placement which can be corrected by doing away with the steel line and running a nipple and rubber hose.

If you go this route be sure that atleast for the verticle run of the hose you pass it thru some 3/4" heater hose for added cut thru protection.

[Scott Stoneburg]

Just a thought, and i dont know the answer. But could the pump listed for a '66 Tripower possibly be intended to move more fuel due to supplying 3 carbs?

[patox]

I think there are those kind of differences..
Summit shows different pumps for the same 389 or 400 if it was for a GTO or a Boneville for instance..

Thats pretty selective!

[punkin]

Did any of those cars have smog pumps or other accessories that might be hanging off on that side? I had an old cadillac that had what I think was a vacume pump and canister for running power doors and air duct valves. Ride leveling now that I think about it.

[patox]

No, none of them.
Export vehicles, to south america.. we dont even knew what emissions were at that time! I think gm even feared there might be no gas or oil over here...

[lust4speed]

Hopefully the fuel pump listed for Tri-Power has the output pressure reduced. Seems like fuel pump manufacturers go for price when ordering springs in bulk and some pumps end up with really high output pressures.

As referred to above, most differences in pumps are input and output directions. I wanted a later deep bowl fuel pump and put up with non-stock directions.

Look for reasonable output pressures when listed and also whether the pump fittings are for 5/16" or 3/8". Check to make sure that I didn't screw up or that the part numbers don't reference a different carb now. Fittings may or may not be facing the right direction. Let me know if corrections are needed and I'll change my list. This was compiled for my 67 GTO cruiser that I sold a few years ago.

Mechanical fuel pump:

With short canister and vacuum return:
Airtex 40521 is short stock replacement without return line and short canister – 5/16” hose inlet
Airtex 40610 is short stock replacement with return line and short canister -5/16” hose inlet
Airtex 110-40610 is also an acceptable substitute from Rock Auto, 6.5 PSI short bowl
Precision Fuel Pump from O’Reily Part# M23081 is short bowl and 6 PSI

With deep canister and vacuum return:
Airtex 110-41382 (Summit Racing Part Number ATX-41382) – 3/8” inlet, 9 PSI long bowl
Precision fuel pump from O’Reily part # M20011 is long bowl and 7.5 PSI