can anyone tell me tell if the au belt tensioner is the same as the EL belt tensioner? also if im using a au block do need to use an au belt or can I just use my previous EL belt?

AU & EF/EL tensioners are the same. If you are using the AU alternator and have modified the AC Spacers then the EF/EL Belt will fit. If you haven't then neither belt will fit.

Refer to item 8

Things required to fit AU engine to EF/EL

1) Sump needs to be modified to fit K-Frame, you can cut and weld the K-Frame but that is up to you, will need engineering after being cut. You cannot use an EF/EL sump as the sump is totally different to AU.

2) Need to use AU/BF alternator or you will need to modify the block and drill and tap mount points to mount the EF/EL alternator.
If you use an AU I alternator you will need to change the plug for the alternator to one from an AUI as these are different from the Mitsubishi alternators.
Note: Believe that the AUII & III and BA alternators have the same plug as EF/EL.

3) Remove the block where the Dizzy (EL) or cam sensor (EF) goes and remove the gear from the shaft and fit to your Dizzy (EL) or Cam Sensor (EF). This will then mean that the gears are matching and you should have no issues, there have been issues with dizzys failing when this has not been done. Some modding will be required to use the existing mount point, extra notch/grind Cam sensor.
Note:Do not try and drill hole in existing EF position on AU block, you will drill through the block.

4) You will need to use an EF/EL thermostat housing as these have your temp sensor and AU housings do not.

5) You will need to use the EF/EL BBM as the uppers are different to the AU. Also us the EF/EL throttle body as some of the plugs are different to the AU.

6) Use the EF/EL wiring loom.

7) You will need to tap the block with an M12 1.5 tap if using the EF/EL Knock sensor. If using the AU sensor you will need to modify the plug.

8) a) You will need to cut the EF/EL AC pump mount spacers down to 30mm to suit the AU block as well as shortening the bolts by 10mmm if using the AU alternator to suit the standard serpentine belt.
b) If using the EF/EL alternator with modified mounts you will not need to cut down the mounts and be able to use the standard Serpentine belt.
c) Alternatively you can use the AU alternator , standard AC spacers and a Serpentine belt from an XH (Slightly longer).

9) Use the EF/EL power steering pump. This is a direct bolt up. The AU pump hose connection is different to the EF/EL.

10) You do not need to change the Harmonic balancer for either EL (Dizzy) or EF Coil Pack.

11) If fitting to EF you will need to use your original Coil Pack or an AUI coil pack as these are different to AUII & III. (different plug)

12) you can use the AU head or fit you EF/EL head, that is up to you.