I just bought a new fuel pump for my Firebird, its a chrome mechanical pump that says it fits, Pontiac V8 301,326,350,389,400,421,428,455 engines. I took my pump out to replace it and I noticed that are are different. The one that was in my motor is shorter with a sharp bend, the arm on the chrome pump is longer with less of a bend. Are there different pumps?? Will the one I bought work?? Thanks,Mike

Might have got one for a chebby???

I would take the old one down to the parts store and match it up.

Can't see the fancy chrome one from under the hood anyway.

Agreed. A lot of those reproduction part house sell parts for both the Chebby and Pontiac F-Body. There are a lot more aftermarket chrome pieces for the SBC engine and they are sloppy in their catalogs. They get lazy and list Chebby only parts as applicable to the Firebird like all of us have ditched our Pontiac motors.

Other bad examples are starters, dipsticks and tubes, transmission access covers, front timing covers...

You just bought it...post a pic or a link to the part...or post the part number.

A Pontiac fuel pump has a longer arm compared to the Chevy. The Chevy pump uses a push rod and therefore has a shorter arm.

Another consideration, most Pontiac's require a 3rd port for the fuel return line. Just capping off the return is not a good idea.
I think Chevy only has 2 ports, an in & an out..

If that chrome fuel pump is made by holley, I would return it and find anything but that pump to put on your poncho. I went thru 3 of those pumps before I finally figured out it wasn't me and was the junky built pump. Look at the RobbMC pumps.

I second the RobbMC pump!! It is a great pump and is built great and looks good also. And the cheaper RobbMC pump will provide fuel up to 550 HP engines. http://www.robbmcperformance.com/products/pontiac550.html

The RobbMC looks like a great pump, however it may be over-kill for the street. I've had luck with Carter fuel pumps and they're only $30. I've never had a starvation problem.
see: Summit - Cater FP

Note: there are 2 versions available so the link above may not be correct for your car.

It is a great pump and lots of room for adding HP to the engine, but the main thing here is the OP never said anything about it's use, so it may be perfectly good for what he needs it for or maybe overkill, but looking at his user name, I couldnt help wondering if he in fact has a Blown 350...lol If that is the case, the RobbMC would be perfect, not overkill...but all this is assumptions since OP didnt provide usage and engine build information!

I have the ROBBMC and I have problems with it. Fuel pressure drops to 3 psi when engine is all warmed up. So it's coming off.

I have the 550 and I bought it second hand, so far so good. He is supposed to be pretty good about working with you to inspect and/or rebuild his pumps so I'd at least contact him.

Yea, I woud for sure contact them and see what they will do for you. Did you have this problem since you recieved it from Robb?

I don't think the pump is 100% the problem. I have to fill up with race gas or AV gas to check.
The problem is in the heat of AZ this pump gasoline has a much lower evaporation rate. It is literally boiling away in my engine compartment.
When the outside temp is above 90 degrees my car is undriveable. So my car has been sitting since April.

That sucks! Do you use stock fuel lines or did you put some after market lines in? I havent had any problems with gas boiling away from the heat and I usually have anywheres from mid 90 to 100 degress with high humidity here in NC. I do have a vapor return line though. You running a stock engine or built up engine?

I have -8 braided all the way from tank and custom pick up I made.
It's all stock....LOL

What kind of custom pick up are you using? I am using the RobbMC Pickup/sending unit.

I cut open the top of the tank and put in baffles so the all the gas don't run up put the tank filler and fabricated a pickup to the area where the baffling is. The pickup is always submerged.

Looks like good work to me Chief but that sure is odd about the pump gas above 90, and I'm dealing with 100 degrees temps every summer here. Is there any chance the set up could be sucking in air between the pump and the tank?

Sounds like a nice set up.