Hey everyone, new to forum. I have a 94' F-250 2WD with the 5.8, 285-75R16 rear and 265-70R16 front and what I think is 4.14 gears in the rear.? It has a flat bed with a dove tail that I use to haul my lawn service equipment on, yes we are talking about a work truck, but I make money with it so I can justify putting a little money in ole Hun. I am looking to improve the MPG and maybe boost the fun factor just a little. From what I've heard, there are 3 choke points on this engine, the intake, the heads, and the exhaust. Since these 3 parts are tied together, it's unlikely real gains will be felt by changing just one. The engine has over 337K mile on it but runs great but plan on doing a leak down and compression test before modding. So here is what I was looking to do. Install an Edelbrock lower intake and port match the top. Seems that the bottom is the choke point more so than the plenum. Gasket match the heads, shave to bump compression to 9.5:1, simple port job (i.e. blend the entrance to the runners and bowl blend, streamline the guide boss and thermactor ports and knock down sharp edges.) From there, remove the stock exhaust and start with a set of Hooker long tubes to 2.25 duals (front tank removed) to an H-Pipe and then to single in/out chambered mufflers with turn down right before the axle. 2.5 is generally recommended for duals but usually with CATS inline. I was thinking of swapping out the cam but for low end toque Idle-5500, I was told the stock roller cam is more than enough. I don't plan to run cats (no emission laws here yet) since that was the main purpose for the AIR system, would it hurt to remove it? I'll just weld in a bung for the EGR on the LT's to retain the EGR valve as I've read removing could cost MPG. I was also looking at getting a set of injectors from an Explorer 5.0 and swapping those in. Supposedly those have 4 orfices vs 1 orfice like the stock ones and are supposed to atomize the fuel better and are plug and play, IDK tho ya'll tell me. Like I said, not looking for massive HP, just lots of useable truck torque for when you gotta giddy up and go. Thanks

 

Upgrading the intake is a sound idea but your plan to mix an Edelbrock lower with the stock upper won't work... they won't bolt together. What you could do is port the stock 5.8 lower to match a 5.0 truck upper which is a much better design, and then hog away at the heads as much as you dare... especially on the exhaust side, or keep your eye open for a set of GT40 heads to bolt on, these have bigger valves and flow 20% better all stock. The stock cam is pretty good but it's a little shy on lift so consider adding a set of 1.7 rockers, these will fit under the stock valve covers with some messaging of the oil baffles. Pacesetter headers fit these trucks very well and have the EGR and O2 bungs built-in, and you can safely delete the complete AIR system as long as the TAB/TAD solenoids remain electrically connected. Explorer injectors do perform better but they are more prone to sticking open(I have a referbed set this happened to and apparently it's not uncommon) so you may want to look a new set.
Stock gear ratio would be 4.10 which is great for working but not so much for fuel milage especially if the truck doesn't have an overdrive transmission.

 

This works awesome. Did you get this idea from me (I have hinted this around for quite a while)
I have a majorly ported 351 lower and a massaged 5.0 upper ready for my truck. I used the milling machine to hog out most of the material. There is a lot of work that goes into this. You can get it to the same size (bigger actually) as the edelbrock lower intake. The only difference I can really see is a slight radius difference because the 351 lower is shorter than the edelbrock.

I can duplicate it to a stock 5.0 upper if anyone likes. Give me an email if interested.

 

I have seen this done several times and it was something I considered for my 5.8 but since I don't have access to any machine tools it just wasn't worth the effort or cost when a complete Typhoon intake for the 5.8 goes for about $400 and it has a much better designed lower portion.

 

Hey thanks for all the advice. I might have a set of GT40 heads, guys supposed to check them for me in the next couple of days and let me know. I'm still up in the air for the intake, might just go bolt on instead of modifying. I checked out a set of pacesetter header, 459.00 for a set, seriously leaning toward a set of Hookers, 205.00 and I can turn a bung and weld it in. 1.5 primaries and 2.5 collectors, guess I'm going duals. Was reconsidering single 3", but with my budget and the price of a good bassani Y pipe, just a little outta reach. But right at the moment, I get bigger problems. Was driving the truck the other day and all of a sudden the truck just lost power. Let off the pedal and got back on all was fine, pushed a little farther, and lost power again. The longer I drove the truck, the worse it got. So bad that I couldn't go past 1/8 throttle. Got it back to the house, about 20 miles at 25-35 mph, changed the filter and seemed to be okay. Well it started again, so tomorrow dropping the tank, fixing the sending unit while I'm in there. Oh well.

 

There are no over the counter Y pipes that work with longtubes.. as far as I know, I'm pretty sure that Bassini is made for shorties so it's no good to you. There's nothing wrong with using cheap headers if you have some fab skills.. well almost nothing wrong with it as long as the headers fit the truck decently and don't hang too low. Flowtech used to make a dandy set but I think they threw out the original mold when Holley bought the company because the newer set I have bares no resemblance to the old set I had and fit terrible.. to the point I'd have to hack sections out of the head tubes to shorten them if I was to ever use them again because as delivered the collector is WAY too low and too close to the cross member.
I have always build my own Y pipes for these trucks, buy a 2-into-1 collector, a couple mendrel bent tubing sections and some straight pipe and spark up the MIG. The pic below is the original setup I has with my old Flowtechs which as you can see tucks up there very nicely.

 

Okay, screw it, Hookers LT's, fabbed Y to 3" Aero Chamber muffler and maybe just maybe a short glass pack in place of the cat ( depends on the sound level). Found a 1996 Bronco with Single 3" on youtube,


I want that hollow throaty sound. My truck is a 2WD so might be a little luckier than you on clearance when it comes time to route the system but you got some skill, real clean install there.

What do ya'll think, Can I make mine sound like this minus the cam lope

 

Cats are cheap now. I'd use two cats when building custom exhaust.
Usually they are rated for only 6liters. I don't think it's too much of an issue with our low reving engines, but I don't like the thought of the possible restriction, that's why we are building these custom exhausts.
I use a magnaflow or a knockoff of it, because they have a nice y-pipe built in. Dual 2.5 in/single 3" out. If you use a dual in/dual out it will have an x-pipe in them.

I wish I had my exhaust completed, I'm very interested in the sound. I have longtube stainless headers and 2.5" mandrel bent stainless tubing and dual cats, magnaflow muffler, and stainless 3" tailpipe.

 

I'm doing something similar to Conaski except I'm going to go with shorties. I wasn't happy with the choices for LT's on my F250 considering I'm thinking of swapping in a D60...

But I'm going 2.5 into a flowmaster Y and 3" out. Magnaflow has a tailpipe that I got for my bronc that I'm hoping to use for the F250. It's the 15003 and it's mandrel bent, stainless 3" for $60. Not sure on the muffler yet. I want quiet and I'm going to add an electric cutout. Since I don't like pure open pipes I was thinking of a small, short glasspack just after the Y pipe, then the cutout and either a Magnaflow large oval muffler or a 70 series Flowmaster.

GT40 heads would be great if you can get them.

The loss of power could be a fuel pump, mine did that and I found it was dipping under 20psi under load. At idle it was fine.

 

Im curious if anyone has dyno numbers on shorty/LT. The shorts just seem like so much less bs, and easier on the wallet..

Is it really worthwhile?

 

I'd LOVE to see that. I got tired of every other post saying I lost power/I gained power, I lost low end, I gained low end...

It's a truck and I don't need every last once of HP but if there is a ton of easy HP I want it. My conclusion is that the easiest HP/TQ to be found is in the factory Y pipe. Adding headers eliminates that. But, adding headers and a poorly designed exhaust (for a truck) may shift the power up and end up being not as beneficial.

The final straw for me was that the PO of my 87 claimed to have had headers on the truck only to take them off because of lost of low end power...

So... I looked into my wallet, into the exhaust section and saw that I had just enough to get the parts to start a Y pipe to fit the factory manifolds. Later I'll add the shorties, mostly for looks as I really feel that the most bang for the buck is in the Y pipe. In the end I'll install my 393 stroker and that will make a difference headers vs shorties.

 

Okay, so after talking to everyone on the forum, and hours of searching, I think I've got a plan.

Exhaust:
Hooker long tube headers
Custom made Y-Pipe 2.5 to 3", mandrel bent tube of course.
3" SI/SO Aerochamber muffler turned down right before the axle

Heads:
Iron GT40
Gasket match ports, smooth short radius, bowl blending, just a basic DIY port job
Comp cams springs, retainer, locks (from kit #K358-349-8)
Comp cams Magnum roller rocker kit (push rod, guide plates and studs)
Heads surfaced and cut to bump compression up to 9.5:1

Intake:
Just gonna have to use the stock one for now, but hopefully an Edelbrock one day.

Camshaft:
Comp Cams K35-349-8
This kit comes with new lifters and timing set
Supposed to work well with the SD computer without tuning and still has a subtle lope at idle from what I've read. Not as noticeable as the E303 but still there none the less.

Ignition:
Accel tune up kit
Cap, rotor, wires, and plugs
Check and set the timing to 10*, not worth playing with from what I've gathered.

Fuel Injection:
4 orfice injectors from 97-up 5.0 Explorer, new ones too because I was told there was a problem with the caps cracking on used one or reman injectors
I can get a set of them for 168.00, supposed to be better than the stock 5.8 ones and increase MPG's from better atomizing of fuel.


Induction:
Stock air box with I6/460 intake tube

All together minus machine work for the heads and the heads themselves,
1473.95 from Summit to the door. I think I might have done learned me something.

With the cam and exhaust, it should have a mean sound to it. And with the engine working a little easier and make better use of the fuel, should boost MPG and power (given I can stay off the gas and drive like a responsible adult and not John Force) I mean it is just a work truck, not a 10 sec. drag car. So what do ya'll think, this setup should net me about 270 HP and 350 ftlbs. of torque, or am I just lying to my self. Interested to see what yall think, especially conanski.

 

Sounds like a great plan but I don't like the cam kit.
You're not getting a double roller chain, its not computer compatible, and is your block a roller motor. I can't remember when that started, sorry.

As far as the extra machine work to get studs and guide plates, and extra cost of pushrods, why not just use pedistal rockers that bolt in place. Similar cost I'm sure but unless you're using heavy springs or reving high, I prefer pedistal roller rockers.

 

Yeah GT40 iron heads use pedestal mount rockers which are more than sufficient for truck use so don't bother with all the machine work needed for the stud version. Instead have the machine shop setup the heads for the matching double valve springs recommended for this cam and buy those along with the matching retainers and locks.

Also do not gasket match anything... leave that to the chevy guys that don't know any better. Instead port match the intake to the heads, the port exits in the lower are gonna be a lot smaller than the head ports anyway and you will have some significant port misalignment if you shave much off the heads, so that's the bottleneck that needs attention. However I won't discourage you from cleaning up the heads and and doing a basic port job for future considerations like a better intake, at least it'll be ready to take advantage of a relatively easy bolt-on upgrade.

I like that cam it's the one I have in my 5.0, it makes good power in that motor and should work very well in the larger windsor.

 

You'll find that on the web, shorties have an advantage over longtubes at midrange rpms and longtubes dominate at low and high rpms, but both offer significant gains over manifolds and the stock Y-pipe setup.

Note: Shorties with the stock Y-pipe and cats is a complete waste of time.. zero gains.