cheers Dodgeman.. I've replaced the inline filter now i guess on to the carb tommorrow after work or on the weekend whenever i get it back from the mechanic!

There are two,........... possibly three pl;aces where material is separated from the fuel.
1. Strainer at the fuel pickup in the fuel tank. If one is used in Datsuns [& I don't know if one is] then it prevents small rocks from entering the fuel line.
2. Inline fuel filter in the engine bay. This is the main filtering location. Replace it at any time that you think it could be causing a problem.
3. Gauze strainer under the needle & seat. This is the last line of defence & you need to remove the top of the carb, then the float & needle & seat assembly in order to access it.

Ddgonzal is right, the engine doesn't care what the pump looks like, as long as the mounting flange is the right shape & the arm is the right length, then it'll be good to go.

It is easy: remove your fuel pump, and take it to the store. Compare it to the new one before you purchase.

It doesn't matter how it looks, what matters is how long the arm is.

Wow thanks so much for such an informative post.. With the fuel filter.. I'm running a line filter before the pump.. is there another filter in the pump itself or is there a filter in the carb? pardon my ignorance?

with regards to the early/late model pump the hardest thing i've found is tracking down the difference here in sydney.. I know I have a late model engine.. the replacement pump I bought said suits models 70-73 (on ebay) but doesn't look like the old model pump in the photo... I've been now to auto 1, repco and supercheap.. all have told me the same thing.. they stock a goss fuel pump which is suitable from 71-80 or a fuelmeiser which is suitable for the same year range.. so HOW can i find one suitable for the later model engine if all 3 places are telling me that the pump they stock spans the range???

Thank you again dodgeman.. really appreciate the post

Early fuel pump [front distributor engine] Short arm, will fit but will not work in late engine.
Late fuel pump [rear distributor engine] Long arm. Can be made to fit early engine but arm will break after about 1 to 2 miles [1.6 to 3.2K]

Fuel pumps will push about 4psi of pressure.
The engine can produce about 21 inches of Mercury Vacuum at the inlet manifold without much problem when in good tune. [not 21 pounds of vacuum]

If it's rich, then possibly the needle & seat are leaking or float level is incorrectly set.
If it starves for fuel under load [high fuel demand] then the first thing to check is the fuel filter. These things prevent rubbish from passing through & therefore slowly block up eventually causing a severely restricted fuel flow.
Replace the filter as a first measure. It's cheap & easy to do & could save a lot of grief.

Have a good look inside the old filter to see if the filtering element is still glued to the filter body or if it is detached & rattles around.

The alcohol in E10 fuel slowly dissolves the glue holding the filtering medium in place & if it is detached then it's possible that a tiny piece of rubbish has made its way under the needle & seat to cause low speed flooding while a larger piece may be partly blocking the fuel line leading to fuel starvation at high power settings.

There is also a small gauze strainer under the needle & seat assembly & this might be partly blocked.

well i am in a pickle at the moment because the engine was fine pulling 21 pound of vacuum.. the electronic dizzy was stuffed so went back to points.. now it's running rich and then starved of fuel up hills (according to the mechanic..) sounds like pretty conflicting info.. or to me maybe the cog is out.. so timing is off

by 'cab' I meant cam!

Yeah I had fuel pump from an A15 that actually damaged the eccentric lobe of the cab because it was either too long or of a different angle [can't remember) so there are some subtle differences.

Going electric because the stock one has failed is a big move and a fair bit of hassle if you haven't done it before. Why don't you just buy second hand pump that works? Never had a fuel pump fail in any of my engines though, you sure it isn't a separate issue altogether? i.e Carb float needs adjustment?

You could just change the arm over with the one that is in the car now I've done it before a long time ago with no problems

psi and flow rate don't matter, they are close enough

but my understanding (which could be wrong) is that early A12 and late A12 fuel pumps use a different length arm. So if you fit them one way, it breaks. The other way and it won't pump enought.