which one would you use? The engine is a pretty well built 289 5 speed. what are the advantages or disadvantages of both?

 

I've run autocross on a multi carb 289HP, using a stock fuel pump, no problems. Simple is good. Never felt like running the wires and plumbing for an electric.

 

Mechanical are cheap and reliable. And there are a wide range of sizes to support huge power. Electric is nice even on a carb because you can prime the system after a jet change and not dry start. But, more expensive and complex. I wouldn't run an electric unless I converted to EFI, since you need an electric to make the pressure.

 

I agree. No problem with a good mechanical pump. Electric takes some semi-complex wiring (have to wire in some sort of safety shutoff) and usually a return line. Necessary for EFI, but not for a carb.

 

Mech: Advantages: 1) reliable 2) easy to install 3) less parts to fail 4) no wires to run 5)quite 6) shuts off when engine shuts off 7) no risk of electrical issues. 8) Low pressure no regs

Disadvantages: 1) can not be deactivated by simple means such as toggle switch for anti theft. 2) Limited to about 600-700 Hp 3) low pressure bad if someday you need fuel injection

Electric: Advantages 1) Good for very high HP applications 2) can be quickly shutdown via a toggle switch no inline fuel solenoid required. 3) good for EFI

Disadvantages: 1) can be high power drain 2) can run hot 3) tend to have shorter life span than mech 4) can be noisy 5) electrical issues and related safety 6) High pressure requires a regulator 7) regulator failures 8) can continue to run if engine dies very bad if you have a stuck float

-Gun

 

with an electric pump you wouldn't need the fuel pump eccentric and thus allow the use of a fully adjustable timing set.

 

how many gph would I need for a 289 with about 350hp?

 

I dont know exactly but i run the carter 120 GPH not so much that it needs 120 GPH but that model is built very well... you should be able to find it on summit for around 110 bucks.

-Gun

 

I ran the stock pump making at least that much power and never had issues. I run the basic Edelbrock pump because it's rebuildable.

And the fuel pump eccentric doesn't matter on adjustable timing sets. Mine is adjustable and I'm running the eccentric.

 

I see no need for an electric pump on a NA engine. The mechanical will do a great job, save you money, last a looooong time and not cost much to replace.