cheppibear

Anyone know the volume (GPH) of the 1984 LG4 stock fuel pump and when it becomes a performance obstacle?

I have a 355 making around 325 HP and need to know if I should upgrade.

If yes what should we do with the fuel return line outlet (coming out of the stock pump - the one not going to the carb) if the performance pumps available do not have that outlet?

Currently running an EDEL 650 cfm carb.

Thanks

Atilla the Fun

The in-tank electric pump is known good to 308 crank HP as proven on an engine dyno. If you're running that, then don't bother with another pump on the block, just get a return-style fuel pressure regulator set to about 5.5 psi. If the pump in the tank fails, having one on the block won't save you, since it can't pull fuel through a failed electric pump in the tank.

JamesC

iTrader: (5)

If you don't have an in-tank pump, which you may not (at least my 85 IROC doesn't have one), you might consider the following. According to five7kid, the Carter M6626 is a good choice for the mechanical. It has the return line, and is rated for 120 GPH.

BTW, I'm running an off-the-shelf pump on my 350/330 with no noticeable problems.

JamesC

Atilla the Fun

I was not aware of that pump. Thank you JamesC.

cheppibear

Thanks - Good to know about the stock pump and also what part# would offer an alternative solution that would work perfectly for 30 bucks.