What torque converter should I pick

[Mbosse]

I have a 98 k2500 I’m putting a 383 in. The cam in the motor has the specs as listed in the picture below. What stall should I use it says the operating range on it on their website is 2500-6500 I was thinking 3000 stall speed is that about right or not

 

[Sean Buick 76]

Yes a 3000 stall should be fine. Are you using a lockup converter 4L60e or a th-400? If it’s a non lockup 400 I would stay at about 2500 on the converter and spend some $ on it as the low cost units cause extra heat and don’t couple up too well costing slippage. If it’s a lockup converter then also spend some $ on it as the single disk lockups won’t hold 500 Hp. I run a triple disk circle D converter rated for 1200 Hp and it can be locked up under full throttle in boost. The single disk lockups have a hard time handling a stock 350 at full throttle.

 

[Hipster]

^^^^ Ditto, cheap converters leave alot to be desired. Call a company get one built. It's night and day difference.

 

[CumminsFever]

I had a local company build me a single disk converter. Set for 2400 stall, they claimed it will hold up to 500hp/1000lb tq. While these are diesel specs, I'm sending it nearly it's max capacity, and it definitely holds.
What I'm saying is, a single disk "can" be made to handle the power. Longevity is unknown to me.
I'm gonna cast my vote into the triple disk if you're looking for "the best".
For stall speed, if you get your stall speed set for the rpm your engine begins to make power, it'll jump and go with a quickness!
I should add, my experience here is the 4l80e, you didn't specify your exact transmission.

 

[L31MaxExpress]

4L80E has better longevity with a larger, single disc. My converter builder talked me out of a multiple disc lockup on my 4L85E converter as he said they are relatively fragile and fail quickly. He knew I was making good power and it was in a heavy van that towed as well. Stock 4L80E converter with the smaller, narrower single handles locking at full throttle behind an 8.1 well.

 

[SNCTMPL]

That cam is going to be rowdy, make sure you post up a video once you get it running.
I would call a couple of converter companies and talk with them, this will be an important decision as to how the truck will drive.

 

[Hipster]

That cam is going to be rowdy

yes it is

 

[Scooterwrench]

Your engine is supposed to make power in the 2500-6500 but you don't need a convertor that stalls above the lower limit or your losing that power. If you still intend to drive this on the street a convertor with a 2200 max stall would be a better choice or you will be running around with the convertor slipping and making heat. If your racing the truck then 2400 stall will flare to 2500-2600 which would be just right for that cam.

 

[Hipster]

Crane does the same thing in their catalogs, the rpm ranges tend to start artificially early. @248/252 @ .050 dur wouldn't surprise me if more stall was recommended. Not seeing this anywhere near being "on the cam" at 2500. Converter technology has come a long way. With that cam maybe looking t 850 or so idle speed @8-10 vacuum, might not be enough for power brakes. 2200 stockish converter likely not let it idle properly. His cam is ALOT of duration for the street. Good for a light street bruiser. Heavy 4x4, idk, wouldn't have been my choice.

In contrast Turbo-Action did me a "tight 10 inch". Loose enough to idle, drives around, takes off fine, nail the go pedal and it flashes to 3500. A 2.5k wouldn't let it idle and it would hammer into drive from park. The right converter can make 480 ft lbs feel like 600. Don't want them to tighten up until well into the power band or you lose the torque multiplication effect. Building the engine is only the first step.

 

[L31MaxExpress]

Crane does the same thing in their catalogs, the rpm ranges tend to start artificially early. @248/252 @ .050 dur wouldn't surprise me if more stall was recommended. Not seeing this anywhere near being "on the cam" at 2500. Converter technology has come a long way. With that cam maybe looking t 850 or so idle speed @8-10 vacuum, might not be enough for power brakes. 2200 stockish converter likely not let it idle properly. His cam is ALOT of duration for the street. Good for a light street bruiser. Heavy 4x4, idk, wouldn't have been my choice.

In contrast Turbo-Action did me a "tight 10 inch". Loose enough to idle, drives around, takes off fine, nail the go pedal and it flashes to 3500. A 2.5k wouldn't let it idle and it would hammer into drive from park. The right converter can make 480 ft lbs feel like 600. Don't want them to tighten up until well into the power band or you lose the torque multiplication effect. Building the engine is only the first step.

I tow with a stock diameter custom built converter that flashes 2,900 rpm behind my 383. Drives as tight as the stock 4L80E B82 converter until I romp on it. At idle at 750 rpm, let off the brake and it crawls forward as easily as the stock converter. Around town, 1,000-1,500 rpm it couples well and moves around just fine. That is also in a 7,000 lbs Express van with a 4L85E and tall 3.73 gear. Lay into it and it breaks the rear tires loose easily despite 3,700 lbs on the rear axle.