I was curious about some "take-off" upgrades for the 5.0 compared to what came in mustangs/explorers etc. Is the stock mustang 5.0 intake manifolds any better than the stock '91 F150? I know the Cobra intakes/Heads(GT40) are upgrades but wasn't sure about the stock 5.0 stuff on the mustangs. Got a mustang swap meeting coming up and would like to get some cheap upgrades for the truck in the process.

Thanks

 

The Mustang heads have slightly bigger valves but IMHO the gains wouldn't be worth the effort of swapping them. The stock Mustang intake manifold and single T/B may offer some slight gains at higher revs but is likely to cost you slightly in terms of mid-range; in a truck this is a bad thing.

All in all, I'd say don't do it. Now if you come across a pair of GT-40 or GT-40P heads, that's a whole 'nuther animal. The GT-40/Cobra intake is good but may not be worth the cost on a relatively stock engine. I'd probably stick with the stock intake and maybe do some cleanup and matching on it.

Are you planning on making a camshaft change or going to high-lift rockers? That would tip the scales in favor of the GT-40/Cobra intake

 

I've been told that the later explorers where equipped with the gt-40 heads as well.

 

I used to have a foxbody inwhich I did the cobra intakes/GT40p head swap along with the e303 cam and was happy with the result. I was thinking that same combo might not be too bad in my '91 F150 along with some headers. I really got the itch to get the truck upgrade in all aspects since being down at the beach last weekend and seeing all the jacking up new trucks. I believe these older trucks have a little more personality and would be something different.

Thanks for the tips...

 

The E303 (same as a Crane 2040) cam is really not ideal for a truck. It makes lots of power at higher revs but doesn't have much midrange to get the additional 1000 lbs moving. Look at the Crane 2030 or equal from other grinders with the GT-40 or 40P heads or a 2020 or equal with stock heads.

Samson:
The Explorers used GT-40P heads which although they are a bit better than the GT-40s they put the plugs at an odd angle which interferes with most headers

 

A truck is VERY different from a Mustang; it's heavier & less-aerodynamic, so it needs low-end torque instead of top-end power. And with a '91 block, any "upgrade" you do is as likely to wipe out the engine as it is to make a noticeable improvement in performance. So don't waste the money on "performance"; concentrate on maintenance. The truck will last longer, cost less, and "perform" better.

 

Also realized this truck is speed density so a MAF conversion would be needed also. Might just take Steve83 up on his knowledge and keep her stock and just ride on out. The 4.56 gears should put plenty of power back into the truck since the 6" lift and 36" tires.

 

You don't need a MAF conversion unless you go to a cam with significantly more overlap than stock. Since you want to maximize midrange performance at the expense of high RPM power, you shouldn't be looking for high overlap anyway. There are a ton of S/D compatible camshafts.

 

The truck has developed some 'chatting' in the valvetrain I believe. It gets louder with the speed of the truck. I just got to find time to pop the valve cover and take a look but in the middle of a move. Poured in some Lucas but didn't help...anyone got any ideas?

 

I prefer Berryman's B12 pour-in (~$4 @ WM), or MMO, or a professional engine flush (like BG Products) over Lucas. But until you positively ID the source of the noise, there's no point in trying to fix it. It could be an exhaust leak, a cracked flexplate, a loose heat shield, or a rock in a tire.