Electric fuel pumps? (carb'd)

[RITTER]

I am assuming its for the GP in the picture? Just for fit or mounting make sure that they have the same basic tank size and shape as the 81 thru 87. I would assume they do but you know what they say about those who assume.

SPECTRA PREMIUM GM306A Fuel Tank shows fitment for all G's 78-88. Honestly, I'm still not positive! Ebay sucks

There are quite a few different tanks offered for the GBody's. They are all the same dimesions and capacity, just different baffling. The GM306A is the correct replacement for the Grand Prix

 

[jrm81bu]

Nah bro, I made sure to read up on the specs before I purchased it. It's range is from 60 to 90 PSI. In any event, I ended up running 2 fuel pumps -- kept my inline pump where it was, being fed by the tank pump (a lotta 1/4 mile racers do that). Lemme look up the part I bought again just to confirm...

Edit: yep, here's the part number EP381, ACDELCO. Specs: 50-60gph @ 65-75psi. Flow is 80 GPH = 255 LPH. In any event, with 2 pumps it will not run as hard and I'm certain I'll get the flow rate at the 50psi that my motor needs. And so should the OP if he decides to use the same P/N.

That EP381 is not for an '87 Monte 4.3L. Its a pump for the newer model 4.3L motor and fits models all the way up to the '97 454 full-size trucks

That's why I questioned the part about beinf for a g-body Monte. They would have only ran with around 15psi.

 

[dogsht]

Motorsholmes I take it then that the exterior dimentions are the same from 78 to 88 which sounds familiar so it should fit fine with the possible exception of the filler neck behind your plate can vary a little bit in the bend.

454muscle, Have you been driving it since you put this new fuel pump set up in?

 

[454muscle]

454muscle, Have you been driving it since you put this new fuel pump set up in?

Just briefly before putting in the garage as the weather got very cold very fast. It idled a lot better and had much better throttle response. Waiting for warmer weather now... I guess we'll find out how well it drives.

 

[454muscle]

There are quite a few different tanks offered for the GBody's. They are all the same dimesions and capacity, just different baffling. The GM306A is the correct replacement for the Grand Prix

Don't you think he'd need a baffled tank, if he decides to use an in-tank fuel pump? The Grand Prix's didn't have baffled tanks, I don't think.

 

[RITTER]

There are quite a few different tanks offered for the GBody's. They are all the same dimesions and capacity, just different baffling. The GM306A is the correct replacement for the Grand Prix

Don't you think he'd need a baffled tank, if he decides to use an in-tank fuel pump? The Grand Prix's didn't have baffled tanks, I don't think.

Oh yeah, definitely need a baffled tank. I was just stating that that number was the correct Grand Prix replacement and that the physical size of the tanks were the same ... so swapping with a TBI tank wouldn't be a problem (or turbo car tank)

 

[trocutlass63]

I was wondering if there is any difference between the GN setup and the 4.3 TBI setup or is it just the pumps? It looked like parts were more expensive when they were looked up for a GN which would suggest there are differences or maybe they're charging more for the same parts because it says they work for a GN.

 

[RITTER]

The tank is most likely baffled differently, since its a higher flowing fuel system. The sending units are a bit different as well. The TBI system is a great replacement tank for any carbureted setup. If you are running (or plan or running) fuel injection, I would opt for the '84-87 Grand National fuel tank Spectre #GM307C and the GN sending unit and pump :idea:

 

[trocutlass63]

The tank is most likely baffled differently, since its a higher flowing fuel system. The sending units are a bit different as well. The TBI system is a great replacement tank for any carbureted setup. If you are running (or plan or running) fuel injection, I would opt for the '84-87 Grand National fuel tank Spectre #GM307C and the GN sending unit and pump :idea:

Ok thanks, I was planning on eventually swapping to a carbureted 455 and was looking into an in-tank setup but wasn't sure which would be better.

 

[dogsht]

As mentioned in my long post and in my signature I ran the in-tank setup with Mallory 4309 return style fuel pressure regulator on my 509ci 800cfm Q-jet combo. 3,840 pounds with me & full size spare it ran 110mph in the quarter and the fuel pressure guage never budged nor did the q-jet bowl go empty because it would make the whole pass and then some including a 140 mph back road run and did it clean never a miss or anything that would suggest the bowl emptying. I am not sure what the baffle looks like in a factory 4.3 tbi tank but I know the GNs have a large plastic fuel trap. You can see one here where Bob ran one on his 455 street car. http://www.robertpowersmotorsports.com/EFI_Pump.html

Bobs car ran a 800 Q-jet and 200-4R like my 442. He ran a 12.3 at 110mph and 15 mpg hwy still dialing it in when it was stolen. The new tanks have more of a pie pan looking thing in them but seems to work fine as I have never seen anyone complain that it starves at low fuel levels on hard cornering. Naturally their has to be a limit there but it must be reasonable. Also finding a used baffled tank is difficult and most freight companys will not ship a used tank. Plus most people are not aware of this upgrade and even when doing a motor swap from a tpi 4.3 abort the system because they don't know it and then downgrade it to an old skool gravity fed. :lol: