1. My VH speedo cable screwed into the pulse converter. Is the HZ cable the same or do I need to get something else?

You'll have to get another cable, a HQ Muncie one will probably go close.

2. Does anyone know if the VN extractors will fit in the HZ?

VN headers fit if you move the O2 sensor. Not sure about extractors.

3.Will the HZ V8 clutch cable work with the VN/T5 cable?

Late HZ will, early wont. A late HZ/WB cable may work with the HZ clutch pedal though, give it a try.

4. Ive read the VS tank with the internal pump (that I already have) will bolt under the HZ with a little bit of mucking around. Is it the straps or the filler that need messing with, or both?

That is for sedan/coupe/wagon. Bit harder for a commercial.

5. Does the T5 with pulse convertor fit under the tunnel OK?

Dunno.

6. My biggest concern is where the T5 shifter comes out as I dont want to cut the body. I know auto is easier but I spent 1300 getting the T5 fixed and I really like it. I know the ford extension is a slight improvement, but I read somewhere once that there was a shorter bellhousing that could be used and you just had to get the input shaft shortened a bit. I cant remember where I read it or what sort of bell housing... Or if it was true or bollocks.. Maybe a munchie..? Can anyone enlighten me?

Dunno.

7. I dont have air con but I do have power steering. What combo of 308/304, VN/HZ bits do I need to use to get the VN 304 working the HZ steering rack?

Power steer will bolt straight onto the VN engine, just swap crank pulleys if needed (PS goes on the inside hard up against the balancer).

8. Anything foul on anything that I dont yet know about? Ie alternators that need different brackets etc?

You need to run the VN alternator and bracket.

9. Do I need to change engine mounts or are they exactly the same?

Use the 308's adapters, engine mounts are the same.

10. I believe the commodore 304 sump comes off and the HZ 308 sump will bolt straight on. Yay or nay?

Yes, use HZ sump, pickup and dipstick. Use a genuine 1-piece rubber sump gasket.

11. Yes its an original factory 308 manual sandman, but it doesnt have the original engine, and this combo plus new shocks, bushes, unis, and probably wheel and diff bearings at the very least; should make it sweet to drive. Im not commiting any crimes against good taste am I?

No. Easily undone unless the T5 has fitment issues. That square blade fan won't work with a HZ radiator and V8 shroud, but if you can find a HZ 6cyl A/C shroud (same radiator) it does. Or use the HZ's round blade fan, but may have clearance issues due to the longer water pump on the EFI engine.