[7072]

I am restoring a 70 Judge RAIII. I got the car in pieces, do have the number matching motor and transmission, but no converter. My question is, Did the RA engines or the PD transmission have a different converter, ie; maybe a slightly higher stall than normal?

[SWEETJUDGE]

Thats a good question..... FYI 69 Judge autos had resonater exhausts..
KEY parts in a resto

[SWEETJUDGE]

not sure about 70s..... i just realized thats your year OOOOPS!

[Todd Kozak]

GM used at least two different converters, a low stall and a high stall, in TH400 applications. The high stall or ' L88 converter ' as it is sometimes known in the industry is probably what GM used in the PQ and PD transmissions used in Ram Air high perf applications. The low stall was around 1500-1800 rpm and the high stall was about 1800-2100 rpm I believe. The high stall can be identified by fins that angle to the right as visible looking at the front of the converter.

[7072]

Jim,
That is exactly what I was thinking. It probally had the "L88 converter"
That is probally what I will use, unless someone here has another idea.

[md1twal3]

Not to hijack, but can someone explain what "stall" means in relation to converters? I have always wondered...

[RUFFJUDGE]

Originally Posted by md1twal3

Not to hijack, but can someone explain what "stall" means in relation to converters? I have always wondered...

The stall refers to how high the engine will rev before it starts pulling the car. For example stand on the brakes then step on the gas and see how high your car will rev before it starts pulling the car. Usually the stall will be listed higher than what you will actually be able get the engine to rev. Thing's like you'r brakes, tires, horse power, torque, surface you are on can all effect how high you will be able to get it to stall. A 3,500 stall converter will stall about 2,700-3,000 in most cases. A trans. brake is you'r best bet to get a stall converter to flash to it's max stall rate because it is locking solid at the transmission and not allowing any slip.

Hope that help's, if I didn't get too wordy. Dennis...

[Kenth]

1970 PD used the same converter #8626162, as the PA, PC, PR, PW, PY TH400´s.
Stall ratio 230/2460.

[Held for Ransom]

Kenth O, since you seem to have the books, maybe you can tell me. Converter on the left is from a '71 THM400 (Grand Prix, PX), right is from a '70 RA THM400 (Firebird, PQ), what are the part numbers?

[Lloyd-TX]

Hey Mike:

According to my Dec. 1971 and my August 1974 MPC's, both of those transmissions SHOULD have been OEM equipped with the same converter, PN 8623964. This PN was used on ALL 1967 through 1974 Pontiac A, F, and G V8's with 4V carbs.

The one pictured on the right appears to be like my 8625982 "L88" converter, which I'm running in my blue Formula. Wish I had two more of them!

[RUFFJUDGE]

Yea, cool! The converter on the right is a factory heavy duty converter, you can tell by the extra 7 weld's on the face of it. Our converter company we use does that to their performance converters(they call it furnace braizing). Makes sence they used the heavy duty converters in the R/A cars. Look's like they are the same stall.

Dennis...

[Held for Ransom]

No offense Lloyd, but your number refers to a rebuilt converter (I checked there first). Here is what's on the backside and why I asked my question. The first question was if they were different. I say, yes, they are.

[Lloyd-TX]

No offense taken, Mike. Sorry, but I didn't realize that the reman PN's wouldn't help. Where can one find non-reman PN's for GM converters?

What are you referring to in that last pic?

BTW Mike, could you post a pic of the trans side of that converter on the right? Would like to see if it's got six flexplate mounting bolt holes!

[Held for Ransom]

Lloyd, do you mean the flexplate side (the trans. side is in shown in the first picture)? There are only 3 mounting pads. And I was referring to the "55" stenciled. I wanted to know if it was a PN reference. There is also some stamping on the flat part pictured, but I can't make it out. '71 was stamped AA.

[Lloyd-TX]

HUGE brain fade, Mike. Yes - I did intend to say the flexplate side.

Dunno about the stenclied numbers nor the stamped code - sorry!

FYI, ALL of the 8625982 "l88" converters I've seen (quite a few), have had SIX pads for flexplate bolts.

[md1twal3]

Originally Posted by RUFFJUDGE

The stall refers to how high the engine will rev before it starts pulling the car. For example stand on the brakes then step on the gas and see how high your car will rev before it starts pulling the car. Usually the stall will be listed higher than what you will actually be able get the engine to rev. Thing's like you'r brakes, tires, horse power, torque, surface you are on can all effect how high you will be able to get it to stall. A 3,500 stall converter will stall about 2,700-3,000 in most cases. A trans. brake is you'r best bet to get a stall converter to flash to it's max stall rate because it is locking solid at the transmission and not allowing any slip.

Hope that help's, if I didn't get too wordy. Dennis...

Makes good sense...always wondered, never asked....and I didn't pay attention in trans class in college! Thanks RJ!

[mscicluna007]

The 55 stamping i believe may of described the engine it belonged to possibly the 455.

This one came out of a PQ T400.

Here is some Pics of mine that came out on the weekend.

[Half-Inch Stud]

Originally Posted by Kenth

1970 PD used the same converter #8626162, as the PA, PC, PR, PW, PY TH400´s. Stall ratio 230/2460.

I'm afraid the 1970 TH400 converters for Pontiacs were ALL 13". Fact huh.

I'm afraid the 1970 TH400 converters for GTO, GP, Big Cars, and maybe F-bodies were all the same parts, except the STATOR might have had a fine variation for minor stall RPM difference. merely 200-300 rpm diff in big-car vs "enthusiastic perf", and nowhere near today's 2800-3200 stall desires for basic Street/Strip.

i tore apart a 70 455 Bonneville TQ, and standard 70 GTO TQ and they were identical inside. there is a probability of error on the GTO TQ being non-original, like a swap was done.


Seems an L88 conv, and some Chevy truck convs might provide a modest stall increase, still not anywhere near todays' Street/ Strip technology that yields stop& go tightness with stalls that yield excellent 60foots. is my opinion that the converter stall RPM needs to be at the onset of the engine's RPM peak TQ. that would allow the torque multiplication to happen without loading the engine down.

[johnta1]

Here's a Service News chart from 1969:



hmmmm....

PY cuts the res quite a bit, hard to read.

Anyway, hope this helps.