I potentially have a motor with no head and am searching for an L18 head to buy.

People have offered me heads from L20 motors.

What is recommended for an L18 1200 ute build?

I don't know anything about L series only A series motors. Cheers in advance.

In other words, is there any advantage to using anything other than an L18 stock head?

Check Ozdat... A87 peanut head is best w53 ok but has small Ports into head. Bigger valves than a87 the u67 and v91 are low,comp heads.

Get that Reco one and upgrade later maybe Jeff. But, only if it really is good.

Depends what you want to do with the motor or car that receives it but
The d21 Ka24e bolts straight on just needs 3 mods
1 oil drain on head easily blocked with insert or Devcon
small gasket goo sealing at the front of timing cover
Ka24e pistons or Mazda Fe3 pistons for more compression
Ka24e engines in the states for SCCA made 340hp
Cleaned up ka24e head is shorter in height & with 2 valves
inlet & one big single exhaust outflows any ported L head.

Otherwise just use the close chamber A87 or best get an LPG
head from a 200b LPG only model same as rare 1600 SSS head.

L16 or L18 SSS heads were 219 casting number the A87 L18 head will likely have similar issues and that is corosion and you do not know where that may be.

L20B heads and V91 Bluebird heads while newer do need chambers welding up to bring the compression up.

For a road car I would go with a Stanza W53 casting and match port with the inlet manifold, the Valve sizes are no issue as likely any head will need Guides or K Lines and valves,So going up to A87 valve sizes really only applies to early L16 heads as 1971 on Datsun 1600's and Stanza's ran the 42mm inlet and 35 exhaust same as the A87 L18 heads.

Go for the newest casting with the right chambers which is basically a Stanza head and go from there would be my advice.
Anyone who for instance has a 219 SSS head will want big dollars and aside from the casting number and use with a full house Engine build with Webers etc is not needed in fact for a road engine match porting to a SSS manifold with a nice progressive taper to the valve makes better gas speed and a better engine with more flexability and no great loss of power up top anyway.

The best Road head I have done for an L series 1800 was in fact an early L16 with 40mm inlets and 33mm exhaust valves match ported to a SSS twin Hitachi manifold and the valve upgrade was only to 35mm late model exhaust valves,The Gas speed and response with the 40mm valves was superior as a road head to any 219 casting or modified A87 so proving those going to 280Z 44mm Inlets were going too big for anything under 2.2 litres

Inlet Port sizes were 38mm on the 219 casting,36mm on the L20B U67 and V91 castings and the W53 and A87 were closer to 31mm and when considering porting it is best to have a W53 where the process of porting is less likely to find water.

A good W53 will open up to 38mm to match the ,manifold and does not either need or want to be as big as a 219 casting further down the port.
Definately do not go for 44mm Inlets as they are definately way to big for an L18,Better to bore it to 87mm with 1mm OS 280ZX replacement pistons giving a capacity increase from 1770 to 1855 cc,Clutch wise the option datsun 2000 Sports replacment clutch will handle anything an L 18 with improvements can throw at it,They are still listed as there were the standard 2000 Sports clutch and the option with a heavier spring diaphragm which is still listed.