What year is the truck and what rating is it? (F-100, -150, -250, -350)
Too, do you know what your gear ratios are on the transmission?

 

'84 F-150, 4x4, no idea of the gears in the tranny, but, like i said, it is a 4spd with a granny.
Eric

 

Do you know which transfer case you have? The gear reduction of the transfer case--when engaged, of course--and the transmission as well as the rear end ratios may have it geared quite low.

I bet it has at least a 3.54 and the big tires are giving you the effect of a higher ratio.

You might be sure to check the differential tag--or, alternatively, the AXLE code on the GVWR and BUILD decal on the driver's door. If you can post those codes, several of us can help you decipher them into specs.

 

my screams too, it not the engine tho..... if you have mud tires or aggressive tread, you get a crap load of road noise that can be easily misunderstood as engine

 

Ok, Sticker with vin number:
Trans: A
Axle: 18

Tranny casting number, only real number i saw on the side: C13884
Unfortunaly the rearend does not have a tag on it, must have gotten lost somewhere in this trucks twenty something years of service.
The transfer case is a NP208, but i dont see how that would matter, as I dont drive everywhere in 4 low...
I can post the VIN if necessary. As far as the noise, the engine is screaming, tires are BFG all terrains, so they arent loud, and i can tell the differance in noise between engine and tires, its also something you can feel, especially on an older truck. Thanks!
Eric

 

I asked about the transfer case because an option and spec book I have showed two full-time transfer cases used in the Fords. I wanted to double-check the ratios of it if that was what you had.

The code book I have does not list codes A nor 18. However, I will use a book I have at work and decipher them for you and post them tomorrow. I do apologize for the delay!

 

Wow, I really apreciate the help, thank you. Tomrrow i am going to be tearing into the truck, i cracked the front crossmember (yeah...the one that holds the engine...and the axle...and....well, important), so, that should be interesting. But again, i really apreciate the help. Thanks!
Eric

 

I've had good results with the Offy DP and C (prolly what's on this one I guess, from the description...) manifolds too. The Cliffords are just too expensive these days. I doubt they have all that much over the Offy C in a street application. The DP limits top-end power, but it gives a little better part-throttle response and mileage. But the single-planes work just great on an inline six. I was lucky: a buddy had this older Clifford in great shape sitting in his basement, and I scored it for a hundred bucks (twice what I paid for the truck, if it ain't obvious by now... ). There was a 4180 off an '85 Bronco 351 on there at first, but the auto kickdown was needed for the motor going into a very good female friend's truck, so I bit the bullet on a new carb. A Holley 1850 vac. sec. will work fine with a little tuning. With a header, a good baseline (I'm at sea level) is #28 pump shooter, 56-59 main jets, 6.5 or 8.5 power valve, yellow secondary spring. The secondaries open according to airflow demand: a smaller engine will open 'em later and full open will be later, so the same spring that's good for a smallblock V8 (even a 305) may be too heavy for a 300...only tuning will tell. Some folks with heavy trucks might want to put a check-ball in the secondary diaphragm vacuum feed to delay secondary opening. I have generally found this to be unnecessary, as I can tune Holleys in my sleep by now (not too much to it, really...). If there's a flat spot when the secondaries open, try lengthening the accelerator pump shot duration (pump cam second hole or change it) until it goes away, or try a heavier spring.

I think even with 3.08 axles and 33's, putting on a header will make all the difference in the world. Loan Ranger makes a really good point too about the stock exhaust manifold heating up the mixture, as it's rather close to the plenum floor. Not to mention it's too restrictive for use with that cam, which is a dual-pattern (and I'd bet the same one I'm about to throw in Sunday if I don't have to make up these rain days we've been having here this week...). So the additional lift and duration on the exhaust lobe wants to help exhaust flow, and it's got nowhere to go, and backpressure is diluting your a/f mix in the cylinder with EGR. That's where the power's going. Count on it. Even with those restrictive stock exhaust ports, the header makes a big difference everywhere, and I am itching to see what this head I massaged will do...

You'll have to cut the smog pump bracket part off the alternator bracket and likely bolt the alternator from the front, as the #1 header tube is right in the way to get the bolt in. I used a longer bolt and tacked a nut on the back side with the bolt tight so's to get it on there right, then made my blue-flame wrench cut all pretty with the bench grinder and spray-painted the bracket. I also ground down the bolt head a little bit so the inner belt wouldn't ever rub it. The Thorley header I snagged off Ebay ($89 to my door, new) has no starter clearance issues at all, I'm happy to say. Last Hedman I slapped on one of these motors was more of a PITA here, IIRC, but the results were well worth it. If you want the header to last, have it Jet-Hotted. I didn't (SLACKER!), and if it weren't for this here can of POR-20, I would have. Hi-heat paint will just flake off. I used 1 1/2" dia., 1/8" thick stainless washers to mount the header and intake, and I had to notch the bottom row for clearance with the intake runners. It doesn't leak at all. There are two gaskets available: one with big exhaust holes (Fel-Pro # VS 50033 C-1), and one with small holes (dunno, it was in the Victor Reinz full engine kit...). You want to use the small-holer, or the exhaust flanges won't seal. I think it's the one from the earlier sixes, but don't quote me on that, I'm not absolutely sure, check with the parts counter guy.

Do the header before messing with gearing. I predict many happy results. You don't really want to change both front and rear gears, now do you? Carb might be spot-on afterward, too, but the #25 shooter nozzle has always been too small whenever I've done this sort of thing...

Axle code 18 is 3.08 8.8 open axle. Trans code A is granny low 4-speed (balky-shifting extremely tough cast iron truck granny tranny) Same as my '86. Yours is prolly a NP-435 too, but I dunno, it could be a Borg-Warner T18 or 19. To identify it, go here: http://www.motivegear.com/tech_info/...nny_guide.html
You'll prolly have to copy/paste the link, as it likely won't redirect from here.

 

I did call Ford today--as I did not have the codes A nor 18 listed. They told me that trans code A is for a Borg-Warner T-18; axle code 18 is for a 8.8-inch 3.08 open differential. It is a granny-low cast iron four speed used in 4X4's. I do hope this helps!

 

Wow, thank you very much, you didnt need to go through all that trouble, but i do appreciate it. Been spending all day working to get the new crossmember in. But from the sound of it, first thing I need to get some headers on there and make sure the carb is dead on. But, I am glad to hear that the tranny is a prety hoss unit, and sometime i might look into gears, as 3.08 seems kinda crappy, but i am still worried about highway RPMs, as its winding out already. But, thanks again for all the info! I really appreciate it.
Eric

 

I've seen any of the 3 (NP-435, T-18, T-19) used with the "A" tranny code during the 80's. Mine's an "A" with a 435. I don't know if this was really year-specific, I think maybe the factory just used what was in stock at the assembly line at the time. Supposedly Ford switched to the T-19 across the board at some time, but I have several conflicting sources as to when, and IIRC I've seen T-18s as late as '85. The T-19 has synchronized first gear and the other two don't, but all of the three are tough beyatches. I've seen 'em behind 460s taking a bit of abuse. If it's an aluminum top cover, it's a 435; on the B-Ws, the reinforcing rib pattern will give it away.

 

I know the differance between the 18 and 19 is that first gear is synchronized (also the gear ratios are differant), my first gear, granny, is definitly not synchronized so I am pretty sure its an 18, unless the NP 1st is also non-synch.
Eric

 

with 28-29" tires, at 60mph its probably running at 2500(what mine does with 3.08) or there abouts, but with your tires it should be allot lower.

 

The counterman from Ford called me back with part of the gear ratios for your Borg Warner T-18 behind a 300Six in 4X4: it, of course, has a high gear of 1:1--so, to be honest, I can't figure out why it would scream so at highway speeds with a 3.08 rear gear ratio. At any rate, the low gear is supposed to be 4.32:1.

 

Uh... You could just count the teeth on the ring gear and the pinon and do a little math and find the gear ratio. Or jack up the truck, secure it with jack stands, and then turn the drive shaft by hand and count the number of turns the drive shaft makes to equal one turn of the tire. The last way is not as precise unless you have a way of measuring a portion of a turn, but it will get you close.

Just thought of a way to measure part of a turn (if this don't work let me know!)

1. Measure the circumference of the tire (measure a piece of string wrapped around center of tread)
2. put a chalk mark on the tread
3. tape a pointer (piece of a coat hanger) to the bed with masking tape
4. line up the tire mark and the pointer
5. crawl under the truck (jack stands of course)
6. put a horizontal mark on the drive shaft and hang another pointer from the frame or underside of the bed.
7. Both the mark on the tire and driveshaft should be at "zero" (lined up with pointer)
8.turn the driveshaft 1 full turn
9. measure the amount the tire moved (from pointer to mark)
10. now do a little math

Hope that you are still with me!

Here is an example:
tire circumference = 7ft 5 1/2 inches = 89.5 inches
1 turn of the driveshaft moves the mark 25 inches

then use the following formula

89.5 (total tire circumference)= gear ratio (x) * inches turned (25)
so 89.5=x*25 then divide both sides by 25 and then 3.58=gear ratio
Ford made a 3.56:1 so that is the closest to your answer and must be what you have.

With this method you are only limited by the accuracy of your measurements and your calculator.

Hope that this helps