The ute diff will handle it OK.
Dazzasute, if you have the 120Y borgwarner diff, you won't have any problems. If its the jap diff, it will probably get you out of the garage but not much further!

I use the Corolla BorgWarner diff, which is essentially the same as the 120Y's BW, but is 3" wider and matches the track of the front with Stanza struts fitted so you can use the same offset wheels front and rear without looking silly. And they come with either 3.9, 4.1, or 4.3 ratios whereas 120Y is only available with 3.9.

There are 2 different sump locations for 4cyl L series motors. The 180B's L18 & 1600's L16 have a mid/rear sump, and the Stanza L16 & 200B/Bluebird L20 have forward sumps - they are the ones you want. You can bolt the right sump and oil pickups onto the other blocks (L18 and early L16) but will need to either redrill the block or weld a tube into the sump for the dipstick.

I've heard of people having trouble getting the L20 under the bonnets, but I built mine for an L16 and the L20 fits in without problems - I've used some L20 engines over the years. I did pay extra attention to mounting the L16 as low and rearward as possible though.

The oil pump clearance to sway bar isn't much of a problem. The 120Y bar give you slightly more clearance there, and I have spaced the swaybar down from the chassis 8mm.

I use a Volvo 244DL radiator. it has the right height for the 1200 rad support panel, and right pipe locations for the L series. I use a slightly shortened Datsun 1600 bottom hose and a cut down VN (V6) Commodore top hose.

I once had a sunny with a heavily worked L18 in it and killed 3 diffs, but the ute diff is a bit stronger than the sunny's. Your ute should snot with the L18 in it cos I know mine sunny did. Got clocked at 196 kph by a cop and I was slowing down at the time he got me. Luckly only got a ticket for 150 kph............... he was a datsun fan and having a good day!!!!

I'm currently putting an L20 engine in my 1200 ute... its fun. I'm not sure about the differences between the L18 and the L20, but i think they're very similar. I bought this engine and 5 speed box off someone who already had it in a 1200 ute, so all the mods had been made. came with extractors. I still had to make a few changes though
Mods i've made:
-reshape the sump (this was done for me, but it didn't look to hard, and i'd rather do this than modify the engine cross member)
-convert clutch from cable to hydrolic. haven't done this yet, but i'll get there
-oil pump clearance is tight near the sway bar. I've moved my motor back into the firewall a bit so that the oil pump sits behind the sway bar, but i think my car has been crashed (before i got it) the other guy had the oil pump above the sway bar, and he had the motor sitting heaps lower than i do, and had ground a bit out of one of the bolts for clearance.
-the tunnel in my car was too small to fit the 5 speed box with the motor back that far. If you keep it further forward, it should be alright, maybe a bit of massaging with a hammer... i ended up cutting the tunnel out of the 200b, now that was a nightmare, but my original tunnel was full of holes anyway
-remove the fan, and place an electric one in front of the radiator, behind the grill (I scored the radiator and fan aswell) i doubt the 180b radiator will fit, the 200b one definately wouldn't
-gearbox and engine mounts.... (obviously)
hope it doesn't sound too bad, i've heard someone say that the 180b motor fits straight in... I'm probably doing it the hard way
i've got a 120y diff in mine... a real weak spot. i'm expecting this to go first
sing out if you need more info

L series engines are tough little bastards. They can be quite noisy due to rattle chain noise.
I have seen an L18 in a ute so I know it's possible. I just don't know exactly what needs doing.
One thing that definitely needs to be modified is the engine cross member. the oil pan on the L series is the other way round. As for diffs, a 180B diff center is bigger than a Sunny diff center so caution may need to be applied.

how hard are theyt to get onto? is there any major problems with them?

hey im wondering if any one could give me any insite on fitting a L18 motor to a 1200 ute.. i went to the tech section and searched with the search bar but didnt find much.. will a ute diff hold? ne help will be great thanx
woodydat.