Why not just run a smaller tire?

That would be the most economical solution, as eventually, you'll need to replace them anyway. Take about 5"of diameter off those tires, and that truck will be a helluva lot more fun to drive.

 

I have been thinking about that today, but with the 4" lift, I was concerned that 33" or smaller tires would look goofy.

 

Some nice meaty 33's would look good on a 4" lift. I'm running 7" on 35's.

 

Ah, I missed the lift thing, nobody wants to roller skate on stilts.

4.88's, then. A bit more gear might match that stall a bit better.

4.56's will make a 35" tire right around the stock tire to gear ratio.

And definitely examine that plenum gasket if you are going in there, it will suck the life out of your low end power.

 

Ok, so I pulled the intake manifold, radiator, water pump, oil pressure sensor (just because I was in there), ignition wires, plugs, cap, rotor, PCV, serp belt, all of the hoses, etc., and replaced them all. I also had a bad A/C compressor, so I swapped it at the same time, as well as the frozen serpentine tensioner, and the idler pulley. Got it all pulled, pressure washed the bay and replaced all of the parts, and had it running in about 9 hours... it was a full day for sure.

The performance seems the same, so the plenum wasn't the source of the issue, but still feel good that I got it all swapped out.

After discussing with a bunch of people, and searching the heck out of this forum, it is plain that the issue is the combination of the higher stall converter, the size of tires, and the current gears. In my searches, I am amazed at the people that are going up to 2500, 2800, and 3000 stall converters on their trucks, that just seems backwards to me, and judging by the fuel that I am going through, I can only imagine that others are having the same issues. I think its important that people really understand what they are getting into if they run a higher than stock stall, as there are a lot of people recommending it on here, and for heavy trucks that seems like a terrible combination (unless you have gobs of hp, a high revving engine that can still make power in the higher range, or are racing and don't really care about mileage and driveability).

So, I am looking at going with a low stall converter, probably 1400 or so stall, which is about 400rpm less than stock. Additionally, I will be getting some 4.56 gears installed as well. I confirmed that with 4.56 gears, and 35" tires, its already lower geared than the stock setup with stock tires. Final rpm is about 300rpm higher with the 4.56 and 35" tires, so it will be better than the stock gearing, but not too low-geared for highway use. In my opinion, 4.88 would be way too low for highway or towing, since we don't use OD when towing anyway.

Your thoughts are appreciated...

 

I think the 4.56's are a good choice.. I'd grab a 1600~1800 TC though.. I'd also make certain and get one that locks..

I run 4.56's on 35's, and above 60mph that baby guzzles the gogo juice.. It is REALLY nice below 60 though.. I can drive easy and get 14.5MPG mixed mileage.. On the open road 60+mph, I get about 12~13MPG.. strange, no?

As far as the TC is concerned- here is my reasoning- if you bolt onto the engine with several of the popular and easy mods, your going to get a truck that isn't as easy to drive.. You'll have to increase your vacuum reserve to keep it stopped and will wear on brakes/rotors and various other components like that.. I'd personally keep it around stock, but with maybe a much better than stock converter.. realize, at 1400RPM, which isn't too far above cold idle of around 850-950, you're going to be standing on the brakes to keep it still.. also, you're going to be mighty hard on brakes and tranny due to the herky jerky nature of taking off with that thing..

 

Hughes makes a TC for towing that is about 1500 rpm stall, 15LFuel, its called there Fuel Miser TC. The guy said even if I ran ratio rockers, it should be fine.

The Towing version that they make is the 15LTOW, and it has a 1200 rpm stall.

If you have any other TC manufacturers you would recommend, let me know.

 

I am really curious why a lower stall converter would be better for towing, especially in a locking variety? Stall speed is where the converter STOPS multiplying torque, it seems to me that the torque multiplication would be something you WANTED for a towing application?

that just seems really counter-intuitive to me.

 

I thought the stall speed was where the converter amplified torque to the point the engine overcomes the braking power.. as in lower stall rate means lower RPM to get teh torque maxxed..

in racing applications, the higher is better for the rev to get the engine at the peak of the power curve before the brake is released.. if an engine is in the bottom of the 'most torque' band @ 2600RPM for instance, you would want to match the converter to that- so when you drop the brake you floggin' ROLL..

I may be way out to lunch on this though.

 

Have a look at this article. After reading this, I would think that you would want a torque converter with a stall speed a couple hundred RPM below the RPM the engine makes max torque at....... Seem reasonable?