I'll leave the underdrive topic for underdrives I guess...

I wasn't going to worry too much about getting an explorer manifold, but if it is easy enough to get hold of and not too pricey then I just may get myself one to get me thru til I get the s/c.

Are they the bigger, squarer type manifolds that are on the 5.0 AUs or something different?

Can anyone tell me what I should expect to pay for one and where I may find one?

What kind of gain could I expect by just changing the manifold?

Explorer and ELGT extractors were only change between EL series 1 and 2. Power up to 185kw in series 2

Good decision mate.
Yep your right the thicker, squarer ones that are found on all AU's apart from the T3 strokers, EL series 2 XR8's and XH II XR8 utes.

You could expect to pay anywhere from say $300 to $500 on one.
As far as where you would find one, Pretty sure theres a couple on ebay, FTG auto salvage (site sponsor) would have one, i think i may have seen one here lately along side a pair of gt40p's, check all local wreckers and even have a look in the quokka. Also Terry at BPT may be able to help you search aswell.

In regards to gains to be had, i would say you have a noticeable gain in low-mid torque on the street and also have a bit more puff up top. As far as on the dyno you may pick up at least 10rwhp peak power.
All in all i'd say you wont be dissapointed if you pick it up at a decent price.
I reccomend you get it re-tuned after install aswell, just to get the most out of it and to keep everything happy.
Just remember your biggest restrictions at the moment are the inlet manifold and current E7te heads.
Good luck mate, and keep us posted.

Did they also get the 5 or 10mm increase in t/b size? The 185's were 65mm, what are they on the 165 and 170's?

Torque is good... I like torque!

Oh yeah, I forgot to ask. Is it something that's easy enough to swap over yourself?

I just saw one today on my mate's sister's AU that she picked up for $4000 at the auctions. She's got some dude looking at buying it for 8 so I might see if I can swap! Haha

Ooohhh yeah, everybody loves torque.

Should be a pretty forward swap, may need some modifications to EGR set-up like piping etc, if manifold comes from an AU, not 100% sure so i'll let someone that knows answer that for sure. If ya handy with a spanner, patient and mechanically minded i would definately take the task to save some dough and get a bit of a closer look at how things work etc.

I think the bloke thats looking at the AU would bloody faint he took the car home after first seeing it with the explorer, and popped bonnet and saw the ugly HO manifold sittin there. I know i would be pretty spewin. But what do you expect for $8000. Also if ya go ahead with the swap, grab the heads while ya there

Grab the heads, intake, TB & MAF if you're swapping. The rest is the same.

Not all that mechanically minded, patient or handy with a spanner. Much rather pay someone who knows what they doing to get it done. Drop it off then pick it up. Too easy.

Anyways, I'll start looking around for one and see if I can't find one at a decent price.

Thats alright mate, in that case go pay Terry another visit, he would be more than happy to fit the manifold and re-tune it, he may also be able to source the manifold too.