What fits? (Direct engine swaps)

[Kommander Kirby]

So at some point I would like to put a different engine in my truck. It's an '84 with a NAPs Z24 and it's excellent, but I really want something stronger. My goal is to end up with something that can put a 300ZX to shame. I want to put in a new engine, preferably a fuel injected i4, as well as a new transmission, turbo, and have it tuned, etc.
Does anyone know what kind of Engine/Transmission I could swap for the Z24 without major modifications to the engine bay?? I live in California so I'm sure its going to be a b**** to work around all of the smog laws, but can anybody help??

[720]

ka24et,ka24det,sr20det, pretty much any inline 4 but the real issue is wiring and mounts but anything can be achieved, when i swapped a ka24e into my truck i just used the hardbody transmission and wiring modified to fit in the 720 body, the transmission bolted right up to the stock cross member and the driveline splines were the same it fit quite well the one thing is that i have to run a electric fan because the clutch fan was too fat because the 2wd ka transmission is slightly longer than the 4x4 z24 transmission. i just used the stock 720 motor mounts redrilled to fit well you can keep your stock ignition lock because the stock hardbody ignition plug is the same as the 720s plug and the speedo is a plug and play but after that, its just exhaust, gauges and whatever tuning you want

my truck is 4x4 so some of this stuff could be different for a 2wd

[Kommander Kirby]

Thanks man, that's actually exactly what I needed to know. I was thinking about going for the SR20DET, instead of a KA. I also though about using an RB, but I found out that they're quite scarce and the parts are even worse. I'm looking to get about 300 hp if not more, as well as taking the transmission from the SR and putting it in my 720, but I think I'm going to need a new diff to handle the power. But in the mean time, I'm stuck with my Z24, and it just feels down on power and it leaks. Any ideas what might be wrong? Would using Sea Foam be a good idea?

[720]

good luck finding an RB in the US without killing your wallet haha its a cool swap though check it out at 0:20 [youtube]http://www.youtube.com/watch?v=nDFXGb0SWdc[/youtube]
as for the sr20det i dont have any clue other than the fact that its dual cam instead of single like the KA but the KA does have better stock hp and a bunch more torque,
but if you only want 300 hp i know a guy who had a couple 240s with KA's and one of them was over 500, of course with a decent tune/turbo and exhaust ect
i have never had a z24 so i really dont know how gutless they are, my truck when i got it had nothing in the engine bay except wiring, the block, head and lower intake manifold with no carb and it was blown so i figured it would be easier to swap the KA out of my brothers wrecked hardbody .
but you could try and put a carb on although you can buy a used KA for that depending on where you are or you could just try a basic tune up with new plugs wires cap'n'rotor fuel filter and i have heard that an msd coil can help too
and for the leak i would clean the engine the best you can and try to figure out where its leaking from then buy a new seal or gasket for whatever is leaking depending on what it is and how hard it is to change
i have never used seafoam but try it out and let us know how it works!