On my previous 454 I used a Holley mechanical fuel pump(110gph,6-8 psi),1/2" line and 850cfm carb.
My question is would this same set up perform well on my new 496(10:1 street motor,etc.) or will I have to use an electric pump?
I like the simplicity of the mechanical pump(also less noise)but don't want to under rate the fuel system on this new motor.

I wish I new the answer, I am sort of in the bag too. The shop that is doing my cam swap highly reccomends electric for applications that are raced, and they swear that if you hang the pump and lines correctly, the noise isn't so bad. Either way, I still had a carter 172 and 1/2" AN line I just bought to match up with my (mostly) 1/2" SS hard line. So I stuck with it, all they said was that since they welded an O2 bung in my headers that I might want to buy an A/F meter. I guess with NA engines its hard to tell for sure that your sucking foam out of the bowls at the end of the track without an A/F meter, so you'd never know it until you got a good electric mounted out back.
I like the look and less sound of a mechanical, I haven't seen any non-OEM electric pumps that don't whine, but I really haven't looked hard for one either. If its a street ride, you are ok, and there are quite a few racers on TC and elsewhere that do fine with mechanicals, but the way I heard it this time around was that you really don't know that your bowls are pretty much empty w/o an AF meter..
Either way can and will work, I stuck with a mechanical, but it I had a more extreme or forced induction motor, a big electric without a doubt.

if you have 7 pounds of pressure at the carb there shouldnt be any problems the 1/2 line should be plenty of volume

On my 496 we did all the dyno pulls with a Carter 172 in place. At 6,500 rpm it was still ~ 5 psi. The engine dyno still had the electric pump in place, we just left it turned off and let the mechanical pump pull fuel past it. I'll bet that if the electric pump hadn't been left in place that we would have seen higher pressure out of the mechanical pump.

Thomas

I've seen the Carter 172 mentioned quite often,is it suppose to be a better pump than the Holley?

The carter 172 is a 172 gph the holley is 110 gph,I run the cater 172 on my big block no complaints here!

I have used them both.With good results its hard to compare a 110 to a 172 though.

I have the Carter. It works way better than the edelbrock I used to have. The holley was not as good as the edelbrock.

An AF ratio meter is pretty much useless unless you are using a Wide Wide Band Setup. They are down to about $400 for a decent package. But the data logging version is what you really want.

Save your money towards a wide band system not those $90 to $120 setups.

The Carter 172 is an awesome pump and keeps me at 5 to 6 psi at the top end. You do not need anything else if the rest of the system is up to snuff. Good sized fuel log helps a lot, -8 or preferably -10 to the pump from the tank or cell