sman

iTrader: (4)

Looking for a converter for my 5.3/4l60e swap. Which factory converter do I really want? Is there a difference in stall speed for any of them? Are any of them more "heavy duty" than any others?

Circle-D

iTrader: (21)

There is no difference in durability. But you can use a 4.8 converter to get a little extra stall.

Chris

01ssreda4

iTrader: (96)

the stock camaro verters are like 1700 rpm i believe. local guy says with slicks he can stall his up to 1700 although when i had street tires i dont remember being about to do that.

tptransmission

There are different stall converter from the factory it all depends on the were you buy the factory parts. The code on the converter will tell you what the K-factor is which relates back to the amount of torque and the stall speed.

sman

iTrader: (4)

How does one decode this number on the converter?

tptransmission

This is just an example, If you can get a converter that has the original label such as FL9B you will know all the information about the converter such as stall speed, torque rating etc...

Converter Chart
K Factor
Approx. Stall Speed
Marking
142 2024 RPM A
140 1996 RPM B
135 1925 RPM C
130 1853 RPM D
115 1639 RPM E
110 1568 RPM F
100 1425 RPM G
97 1383 RPM H
89 1269 RPM J
85 1211 RPM K

If you look at the tag that is usually on the bottom of the torque converter, there is a code with 2 letters, 1 number, 1 letter. The first letter is the application, 200-4R's use a C, the second letter is the "K" factor, the number is the clutch type, capacity & travel in degrees, and the fourth digit (optional) refers to the cover style, number of mounting lugs and method of welding the lugs.

Cover Style: optional code

4th digit: A = Open cover (no converter clutch) 3 lugs with one weld per lug. (gas)
B = Open cover (no converter clutch) 3 lugs with three welds per lug. (diesel)
C = Converter clutch type, 3 lugs with one weld per lug. (gas)
D = Converter clutch type, 3 lugs with 180 degree weld on each lug. (diesel)
E = Converter clutch type, 6 lugs with 180 degree weld on each lug. (diesel)
F = Converter clutch type, 3 lugs, 245 mm style lug.

For the 298 mm torque converters 4-digit code tag...explaned as follows.

1st digit= application
2nd digit= "K" factor (K x 14.2574)
3rd digit= clutch type
4th digit= cover type

APPLICATION:

B = 250 and 350 transmission,
C = 200/200-4R, 325-4L & pre 85 700-R4
D = 85 and later 700-R4 with 30 spline input

"K" FACTOR: A= 142 = 2024 rpm
B = 140 = 1996 rpm
C = 135 = 1925 rpm
D = 130 = 1853 rpm
E = 115 = 1639 rpm
F = 110 = 1568 rpm
G = 100 = 1425 rpm
H = 97 = 1383 rpm
J = 89 = 1269 rpm
K = 85 = 1211 rpm

CLUTCH TYPE: 0 = no clutch
1 = 300 ft/lb 43 degrees travel
2 = 240 ft/lb 46 degrees travel
3 = 290 ft/lb 44 degrees travel *
4 = 160 ft/lb 37 degrees travel
5 = 220 ft/lb 35 degrees travel
6 = 195 ft/lb 42 degrees travel
7 = 195 ft/lb 30 degrees travel *
8 = 300 ft/lb 44 degrees travel
9 = 290 ft/lb 44 degrees travel #
A = 300 ft/lb 29 degrees travel
B = 300 ft/lb 44 degrees travel
C = 330 ft/lb 28 degrees travel

* poppet valve
# static open poppet valve which is normally open and closes during acceleration.

COVER STYLE:

A = Open cover (no converter clutch) 3 lugs with one weld per lug (gas)
B = Open cover (no converter clutch) 3 lugs with three welds per lug (diesel)
C = Converter clutch type, 3 lugs with one weld per lug (gas)
D = Converter clutch type, 3 lugs with 180 degree weld on each lug (diesel)
E = Converter clutch type, 6 lugs with 180 degree weld on each lug (diesel)
F = Converter clutch type, 3 lugs, 245 mm style lug.

Circle-D

iTrader: (21)

He is going to have the 300MM style converter, so those code do not apply. He basically has 3 choices from the factory.

TMBX - 6.0 & 5.3 engines - stall ~1400-1600
TLBX - 4.8 & 4.3 engines - Stall 1800-2000
VJCX - 4.2 Trailblazer - stall 2400-2600 - this is an 11" 278MM converter

There are other codes, but the first 2 digits is all that matter.

Chris

sman

iTrader: (4)

So idealy I would want one from a 4.2 or 4.8?

Circle-D

iTrader: (21)

Correct

Chris

Ford_Assassin

iTrader: (4)

So a stock 4.2 Trailblazer converter will bolt up to my 2004 4L60e and flexplate with no other changes, correct?

How much stall can I expect with a 6.0 LQ4, Voodoo 60511 cam (222/228 dur, .567/.567" 113 LSA), 3.54 gears, in a 2800 lbs Datsun Z car (w/driver)?

Thanks!!