JUst saw this post . Valiance u pmed me and i gave u a mouth full to think over lol. but here is my 5c for the rest of the guys. the engine bay of your 3.3 is the same size as as the D21(old box shape) ive had both. most any motor will fit in anywere if u have enough money patience and time.we have droped a rb20 and rb25 in the D21 , i have seen 1uz(lexus v8) 1jz,2jz ,vg30dett,vg30det,vg30et and some others too fit into a nissan bakkie.There is a np300 runing around capetown with a rb26dett but ive never seen it.
rb25det needs the firewall slightly masaged to clear in the back ,ull loose the viscous fan and ull need to move your radiator forward with 1 or 2 electric fans. management of coice and u should be good plus rb box. if u dont have the rb box a sr20det box will work but ull need a rb20bel housing or a rb20box but they cant take the punishment of a rb25 fatbox.if u can find a rb25fat box bell housing u could use a vg30/33box. the 2.4 bakkie box will also work but ull have to slot 1 or 2 hole on the bell housing BUT the gearing is crap in this box.
VG30dett will drop in BUT the turbos, steering colmn and top of suspention will fight for the same space. ull need top mount turbo manis to clear here.the motor should bolt up to the bakkies box. there are some other issues but not too hectic maybe some trimming of the inner fender under the bonnet.
1uz has some issues but so do most other motors.u can use a 21R(W58 i think) box with 1uz to 21R bell housing.
1jz/2jz just as long as RB so same masage rules apply.21R gearbox with 1jz/2jz to 21R bell housing.
there are other issues like engine moutings, clearances, gearbox,and gearbox mounts, management, radiator,fans, piping if u go turbo route,wireing, etc etc.
Now u already driving a 3.3 so fuel consumption isint the issue. but if what ever motor is setup properly it can be as frugel as your rightfoot allows. if its setup as a daily and not a speed monster u could have some reasonable results . but believe me and ask the guys here once u have a 6cylender and its turbo charged sounding sooooo good ull quickly chase after that sound and any hope of resonable fuel consuption goes flying out the exhast hehehe.
but i promise u,ull love driving it, its fast different and scares the shit out of the neighbours.
and please get better brakes, yes u have 2 pods up front ,but still drums on the back. 4 pod r33gts bolts straightup. im working on a rear disc conversion for my d21,i just hate rear drums.