I have a 1994 f150 4x4 with the 300 in it. Manual. I did add a chip, and plan to add cold air intake so atleast it can get out of its own way. Has 140,00+ miles on it. Was told and does seem like it was well maintained mechanically. Is it worth, at this point, switching to the synthetic oil?? Is regular oil best at this point?? Ive had it less then a year and changed the oil when I first got it. I use high mileage 10w30 Pennzoil. Is this enough?? I'd like to keep the truck as long as possible. I'd like it to last and be the best it can be. Thanks in advance for ANY input.

 

There is nothing wrong with using a synthetic oil other than expense depending on how often you change it. Many have found that synthetic to leak more past worn seals and gaskets compared to regular. Ford recommended 5w-30 or 10w-30 depending average temperature in your area, and of course they recommended Ford/Motorcraft oil. I think any quality brand of oil will serve just fine. The Motorcraft oil filters are good quality and cheap. Normal service schedule is 5000 miles or 6 months and the severe duty schedule was 3 months or 3000 miles.

There is a schedule to check, service, or replace wear items and functional fluids on the truck, and it should be followed if you want to maximize the life of the truck. Get a hold of the Ford schedule and use it as a guide. At this point these trucks are failing in ways that Ford never envisioned so every now and then there are some real head scratchers, but this forum is a great resource for trouble shooting.

Vacuum leaks are common and at a minimum cost power and economy so check or replace you vacuum hoses.

If you want to do work yourself get a copy of the Ford workshop manual. If not find a competent mechanic and make friendly.

I am sure others will chime in.

Good luck.

 

Take the chip out and forget the hot air intake. The factory intake is hands down the best cold air intake for the truck. You can boost the performance without a chip by bumping the base timing a few degrees and it's free.

The which oil question will yield hundreds of opinions. Use what you are comfortable using. Cheap dino oil from Walmart or full synthetic from Amsoil will all work fine. I prefer ~5k oil changes on these truck so I use Ford semi-synthetic 10W-30 and a Motorcraft filter. Easy on the wallet and exactly what the factory recommends. YMMV

 

Thanks guys for the input. I'm a youngin,
40. I do not mind learning my way through this. I do what work I can myself and have been able to do a few things so far. I don't comment often but ALWAYS refer to this site for info. Its great for pointing me in a direction but I learn best by doing it myself. I also use motocraft oil filter and change every 3-5000.
​​​​​​​Base timing, for that I may need to get an Haynes manual. Not sure how/where this is done. But will look into it. The chip is from Great Lakes Auto, and best I can tell it works. Does it give me the promised up to 50hp up to 40% torque. Not sure I'm not a dyno test.

 

All that chip does is advance the timing electronically. You can accomplish the same thing by bumping the base timing as previously stated. Since you already own this trophy device and you think it works then leave it in place. I'll advise you again to not install an aftermarket hot air intake. Keep the factory cold air intake in place then spend your money elsewhere like a full tune up with copper plugs and new quality plug wires, cap and rotor. Add in filters. Good to go.

Check the driver side door jamb for the B-pillar sticker to see what the Axle Code is. If you are stuck with 2.73 or 3.08 gear ratio then you need to seriously consider a gear swap to something a little numerically higher.

 

I won't personally put pennzoil in anything, but it's a 300-6, you can pretty much put any commercially available oil in it, as long as you're changing it at decent intervals with a quality filter, and it won't care, it's an extremely robust platform.

 

I've put Mobile 1 in everything used that I purchased to keep. Been my experience that it has not exacerbated any existing leaks or created new ones.

Rather it seems to me to refresh aging seals/gaskets... but that's just me. The spots/build up on floor and engine compartment definitely was reduced.

My 94 was owned by an individual who never changed their oil & other consumables except with what on hand at the quickie change place.

Nothing was name brand, but at least it was changed regularly.

When I went into the engine you could tell where the "synth" had dissolved cooked oil accretions, waxy build up on the tops of the heads & splashed areas in the crankcase.

Your results may vary.

 

Yellow bottle is good stuff, check out bobistheoilguy.com for all the oil info you can imagine. The 300 has a flat tappet cam, so I would prefer higher ZDDP. Ergo, I use 15/40 Diesel oil from Walmart in mine with any parts store filter I find on sale. I am guessing stock fill was probably 10W30 for most climates.

Change it hot and change it often.

Agreed dumping the 2.73:1-3.08:1 for a 3.55:1 is cheap and easy. Almost every 302/auto truck I have seen has a 3.55:1 diff, I plan this same mod on mine. Probably going to just swap the entire axle as I am too lazy to regear another. The 3.55:1 with stock size tire and a manual yields around 2400rpm @ 70mph by my math.

 

Like the others stated, find your gearing sticker and post it up. You want at a minimum a 3.55 rear gear. Another member on here went from a 2.73 to a 3.73 and not only gain some pep, but picked up some mpg as well.

 

I was just about to ask about gear ratios when I found this...gotta 94 extended cab short bed 351W swapped to a 4bbl (yes,I bought it that way) but I can tell it was built in 94...she winds out on today's interstates at around 80 to 85...anyone got recommendations? Yes,its a E4OD trans

 

Not sure what the ask here is with your Frankentruck. The computer was left to run the transmission but do you know if the engine coolant temperature and air charge temperature sensors were left in place? If not the ignition timing may not be optimal. What gears are in the truck currently?

 

Yes,the gauges all work... I should've updated as soon as I found this...the engine and tranny are still being controlled by the computer...as I showed in the pics before the tranny sensor on the EFI is now on the home-made bracket on the choke side of the 4bbl...flushed and changed the fluid and screen and tranny is smooth even in overdrive...on the door jam it says "19" for a 3.55 rear... I found a 94 410 rear but its 4WD...will it bolt up to ole Frank?

 

Hunh. I have a 94 5.8/E4/2wd/3.08 with some up grades & it buries the needle & still wants to go more, but I've yet to see it hit the limiter in motion.

 

It'll hold 80-85 on a straightway but will start losing on hills...gonna try playing with the timing and see if that won't make a difference....just for reference,this thing sounds awesome with dual exhaust and hearing the 4bbl sound like a Eureka vacuum cleaner,but I WOULD NOT RECOMMEND AN EFI TO 4BBL SWAP...UNLESS YOU CHANGE EVERYTHING....I keep smelling fuel at the tailpipes...can it be flooding and that choke my power?

 

Believe the majority of us here in our little corner of Ford Heaven, very few encourage it.