Check this out:


https://www.ford-trucks.com/forums/5...installed.html


Vince

 

503905 = 503901

Just a different picture on the box.

 

yup, same cam. dunno why they offer it as two different cams. me thinks one is "efi friendly" while the other is carburator only...?

i dont like the bigger cam crane offers. it showed to much peaking on the DD2K. the one i suggested maintains a stock like power band...smooth n flat.

 

Is it expensive to get the heads ported and polished?

 

ppffttt, dont even ask LOL.

i was going to do all my own work to my spare 300 head but ended up having a large but skinny crack on the #5 exhaust. i was going to really go at it but i guess im not now.

i would saw for the work that needs to be done ur looking at $500 just for labor and machine work. add another $300 for new springs, guides and seats.

 

A good port job can cost a ton of cash, but you can get good results on your own as long as you don't get carried away. Just clean up any obvious obstructions and smooth out the casting flash. It isn't what you take out that matters, it's what you leave behind.

 

There was a big thread about porting probably 2 years ago. There's a little hump in the exhaust port that actually needs to remain there. It can be smoothed out, but torque drops dramatically if that little hump isn't there. If I recall correctly.

 

Now this is the kind of stuff i can get into, what works with what and what dosn't.

i just got my hands on a 89 F-150 XLT Lariat Longbed from my pop a couple of days ago. Ive been cleaning it up all day and was wondering what would be the best mods to get all the torque possible out of my 4.9L for towing purposes.

much abliged

also, fuel gadge acts up, the rear tank is the only working one and when its full the gage reads half and when it gets to about 3/4 full it just drops past empty and i have to guestimate how much petrol i have left.

any clues?

 

Hello and welcome to the forums. First off, considering that you're posting on a thread that's almost two years old, it shows you're off to a great start by using the search feature. It'll help you find tons of information.

As for the gauges, stock Ford gauges are known to be pretty poor. I'm exceptionally fortunate that my all the gauges in my '81 not only work, but are accurate. It's almost unheard of.

That being said, it's hard to tell why they don't work. It may be the voltage regulator on the back side of the dash is dead, the gauges themselves burned up, or the senders stopped working. The oil and temp senders are on the engine block, and aren't too expensive to replace. The gauges themselves are several hundred $$$ each new. The fuel gauge is most likely because of the fuel sender, which is located in the gas tank. They wear out after a while, causing sporadic fuel gauge behavior.

9 times out of 10, after you replace all of the gauges, and get them all working, they're still only mildly reliable. The best thing to do is to go to aftermarket gauges that actually read temperature and oil pressure, instead of an electric signal from the engine. They're much more reliable and accurate.

Have fun!

 

This is an ancient thread.

Everything that AbandonedBronco said. Make sure everything is already working before modding.

For torque...on an EFI, you've already got the good intake & exhaust manifolds. Cut off both your cats, junk them, the muffler, and the rest of the tailpipe (save the the Y-pipe, which is a very good design), weld on a 2.5" aftermarket converter & your favorite cat-back or custom-fab exhaust, not too big. A 2.5 single is as big as you want to go. A 2.25" single is great. Front tire exits are fine, preferred even. These motors can't tell a $400 Borla muffler from a $20 Thrush, so as long as it's "free flowing" you're good to go.

Next to do is advance your stock camshaft 4 degrees (OK on 2.25" exhaust). Ford retarded it 4 degrees for smog purposes, but advancing it gains everything, and nobody has had smog problems with the mod. If you can pull your timing cover & play with timing gears, you can advance your cam. I forget if the stock gears can be remounted or are adjustable, or if you need to buy total replacements. Carbed motors came with steel timing gears, EFI with composite gears. Steel gears can trigger your knock sensor, so you're pretty much stuck with fiber gears, though there's nothing inherently wrong with them.

Probably equal with the cam advance is to replace your rockers with stock 1.6:1 big-block Chevy rockers for more lift. Still plays nice with your OBD-1 computer, and I think they're just a few dollars each. Easy project. Your biggest annoyance will be disassembling/reassembling the intake manifold.

These motors are borderline underfueled from the factory. If you are ever going to do much WOT work, you'll want to upgrade your fuel injectors & fuel pressure regulator. The stock unit is non-adjustable, but it's fairly easy to retrofit an adjustable 5.0L Mustang regulator. There's threads on this board about it. Stock injectors are 12lb/hr, which is tiny by any standards. 19lb injectors, which are stock on any other Ford vehicle, are plenty fine for even a modded 300.

Beyond that, you have to get invasive, and a truck cam is next. Most people like a dual-pattern cam with a 260-degree advertised duration, which maintains torque & adds significant top-end power. They usually work with the stock computer, even though the cam manufacturer will say it won't. People have reported passing smog tests with the Crane 260H cam & stock computer (SilverStreak, if I recall correctly). Melling makes a truck-specific cam that I think is really, really neat. It has short stock-style duration (195 degree, etc.) and high lift with aggressive ramps. Think square lobes. Supposed to produce great, great low-end torque.

Once you get cammed, you've got a rockin' motor, probably well into the 300ft-lbs range, with great throttle response. Next is to look at a custom computer tune. Sorry, your computer isn't programmable, and it's capabilities are limited, so you'll have to find a custom place with a dyno, or upgrade to a mass-air EFI system. Check out Ford Fuel Injection. They should have information on retrofitting & reprogramming a Mustang/Bronco MAF EFI system to work your 6-cylinder engine. The "Gold Standard" is the rare factory 1996 MAF EFI 300.

Once you get a capable EFI computer, a port & polish on the head is required. (port & polish may require additional tuning- probably go hand-in-hand)

But you'll probably find satisfaction with the cam advance, rockers & cat-back. You could probably do that all over a weekend with a helper.

 

If you have electronically controlled Ford fuel injection, you are pretty much stuck with stock everything. theres no modding the computer that controls the FI, one. So opening up the intake bowl & port matching- you can do it yourself, actually, its no big deal- serves no purpose because the increased flow cant be used- the computer, again. Part of the FI combustion chamber design that makes it work with fuel injection also heavily shrouds the intake valve, unshrouding the valve removes design aspects that make it work w/ FI.
Simply put, you cant get there from here unless ypu scrap the Ford FI & build your own "megasquirt" system.
The hop up fun requires a carb setup, no way around it. Its a lot of work & $ for no result.
As far as modding for carbs, all sorts of cheap/elbow grease mods make for a nice increase in power AND MPG. Getting real big numbers out of it requires real big $, however.
Nope, that fuel injection is an albatross around your neck.