Wanting to put a new engine into my '02, any suggestions?

[Riley'024x4]

Hi all,
This is my first post so forgive me if I leave out any vital information..
I've currently got a 2.7l petrol 3RZ with 320,000km's on the clock and only running on three cylinders. I'm having nothing but continuous problems and, although it can be fixed, i'd rather pay the money to get an engine that I know will last than fork out the cash to fix something that will more than likely die on me.
I'm slowly learning, but I don't know much about mechanics so any and all advice would be greatly appreciated.
I want to put a Turbo Diesel in, but what I don't know is if it is actually possible and what engine would offer me the most bang for my buck?
Thanks in advance!

[john253a]

Deisel in general just equaled massive $$$ and would be cheaper to buy one already an another car
L series engines are 4K recon short or 3-4K second hand complete (whole car can be had for less)

money being money the cheapest is going to be a Holden v6 with t700 second hand kits with good engine and trans go for 1500 up
Next would be a Toyota 2j

Other options done on a daily basis are
Lexis 4.0v8, sr20, Holden 5L but that's old and heavy, Holden ls series with either 4l80e or import a 6l80e
If you don't mind dropping 12-13k on an engine and trans then another 3-5k on diffs a 6.6 duramax Alison6 speed auto and Dana 60-70 diffs