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What stall torque converter and rear gear ratio should I run with a 5.3 LS for a good highway/street balance?

The two work together. Taller (numerically lower) gears raise the effective stall; shorter gears lower it.

What sets the right stall speed (Speedway):

Stall speed is how far the engine revs against the brakes before the wheels turn. A 2,700–3,000 converter should footbrake-stall to about 2,700 rpm depending on the vehicle.
Match it to the power curve. You want the converter to lock up where the engine starts making real torque, so a bigger cam wants more stall.
Resistance raises stall: a heavy vehicle, large-diameter tires and taller (numerically lower) gears push stall up; a light vehicle with short gears and small tires brings it down.
Give the converter maker everything: vehicle weight, displacement, compression, cam specs, rear gear, tire diameter, fuel system, and transmission model and year.
Speedway's examples: a 2,800 lb street rod with a mild-cam 350 and 3.50 gears → 2,000–2,200 stall. A 3,350 lb car with a rough-idle cam, 10.5:1 383 and 4.11 gears → 3,200–3,500 stall.

Give the converter maker your final gear ratio and tire size along with the engine specs — they pick the stall to suit the whole combination.

What we recommend

For a stock 5.3, keep the stock converter (NBS trucks run about 1,400 stall) and run 3.73 or 3.55 gears for stock-like cruising with some pep. For a stock or mild-cam Gen III, 2,200-2,500 stall is a good balance of performance, streetability and reliability. With a cam, match stall to the cam: we've seen an LH6 5.3 with a BTR Stage 4 V2 truck cam, a Circle D 2800-3000 converter and 3.90 gears cruise at 2,250 rpm at 70 mph and get 18-22 mpg highway over 27.5k miles, though in hindsight a 3400-3600 stall would have suited that cam better since the 2800-3000 surged slightly at stoplights.

Check this first:

Check the cam card's recommended stall range
Confirm your current rear gear ratio and tire size

Based on what we've seen work across our own builds, our friends' builds and the wider LS community, reviewed by our lead tuner (20 years of LS tuning). Every combination is different, so use at your own risk and check our safe tuning limits before any wide-open pass.

Go deeper

Check this first

Note cam specs, tire size, and current rear gear.
Check whether the current converter locks up in overdrive.
Decide the highway cruise RPM target with the gear calculator.

Try this, then this

1) Stock to mild cam: 2,600-2,800 stall + 3.42 gears - the sweet spot for street/highway.
2) Cammed 5.3: 3,000 stall + 3.73 gears to keep it in the powerband.
3) Tune TCC lockup for 3rd and 4th; add an auxiliary cooler.

How you know it's fixed

Snappy around town, locks up on the highway, cruise RPM and temps where you planned.

Still not fixed?

If highway temps climb or it never locks, the issue is TCC tuning or cooler capacity, not the stall number.

Every option we know of

Maker / product	Part #	Fits	Price	Where	Status / notes
Circle D Specialties Street/strip converters	built to order	4L60E/4L80E	$800+	Circle D direct	Built to order Call with cam, gears, weight for the right stall
Yank Converters Truck series converters	built to order	4L60E/4L80E	$700+	Yank direct	Built to order Known for tight, efficient street manners
FTI Performance Street/strip converters	built to order	4L60E/4L80E	$700+	FTI direct	Built to order Good value in the custom-converter market
Fuddle Racing Budget performance converters	built to order	4L60E	verify current	Fuddle direct	Built to order Smaller shop - lead times vary

Prices are approximate as of September 2026. We list every option we know of, including small shops and used parts we can't link to. Confirm fitment with the seller.