Dodgie has been down this road recently and would be able to provide anyone with a pretty good account of good, bad, worked, didn't etc.

Who is Dodgie?

http://www.fordmods.com/forums/profile. ... ile&u=4113

I'm Dodgie,
I've spent some time porting my lower HO, and shouldn't have bothered...
The upper of the HO flows about the same as the whole Explorer set, (at around 189odd v 178CFM av), and you couldn't expext to get more than that porting or changing the lower.
Then the lower Explorer can be ported to well in excess of 200cfm (more like 240+) which is heaps for even hi-performance heads.
A stock HO manifold flows 136 av CFM stock (upper + lower) and are just rubbish! I would be surprised if you could suck 280 hp out of them.
Next to the factory headders they are the worst thing on the engine.
The Explorer manifolds can look nice, and leave room for other mods, which the mod bug will help you out with.
Heres what I did with mine to keep a factory look.
http://gallery.fordforums.com//showphot ... 500/page/1

Changing to the Explorer manifold will leave you with the stock heads being the next big restriction, but will result in around a 12-15% gain over stock.
Together with a 65mm tb & egr would be the best set up for most 5.0l donks.

Another rant about how hopeless the stock HO manifolds are...
http://fordforums.com.au/showthread.php ... t=Manifold

G'day Dodgie.
So what are your thoughts on a different lower inlet manifold, like the Holley that was suggested above, being mated to the upper HO inlet? Would that combination flow the same as the Explorer?

Why bother spending money on the HO manifold when you are going to be limited to what the upper flows.
Theres only so much you can polish a turd...
If you realy want to change the lower only, I still have my ported HO lower lying around you can buy off me for alot less than that Holley stealth lower.
But as I said there is limited potential with the HO manifold.
I did a search on the coral forums to find what they thought of the HO,
http://www.corral.net/forums/showthread ... lth+holley
but there is not much talk on the subject, so I take it that they don't even bother with them.
What are your plans for your car, and has the mod bug bitten yet?

Last edited by dodgie on Thu Apr 21, 2005 11:39 pm, edited 1 time in total.

Plans for the car?
Well the bug has bitten but is being tamed by the wallet monster.
The main reason I asked about the Holley lower inlet was primarily for stealth. If for example my insurance company doesn't want to approve intake mods then its harder to disguise mods if their assessor actually knows something about Ford motors and the lower inlet would be well obscured my my engine shield.
And yes, I am aware of the very restrictive nature of the stock inlet manifold and E7 heads on the standard 5.0 motor but money and insurance are big obstacles.
Ideally an Explorer manifold, larger TB, roller rockers and decent flowing heads would be all I'm after. The rest of my car is fine as it is.