Torque Converters? lock up or non lockup?? Single disc or Multi Disc??

I just went through this same issue with my 68. I'm getting a non lock up 2,500 stall for it to go along with my new AOD conversion. Here's why -
Lock up has a 2 piece input shaft which is weaker than a non-lock up that has a one piece input shaft (meaning it wont hold as much power, and / or as long). The lock up will swicth to the second input shaft in OD which will stop it from slipping to stall speed. When it does so it takes off pieces of material that end up in your fluid that can cause damage. However you'll get better gas mileage with a lock up though. I'm not sure how much better. Everyon I talke dto said do the non-lock up unless you do a ton of highway driving, and need the gas mileage. Not sure if all this applies to a 4.6 w/ am AOD-E. My 68 is a 302 with a AOD. My looser LS1 friend has a 3,500 stall in his auto. Pretty fun to ride in ! I'm not that worried about the gas mileage for my 68 even though I'll drive it on the highway the stall speed in OD is supposedly helpfull too, and I want my stuff to last, and not break !

performance wise should be the same other than in OD -
BTW - your ET sure is fast w/ your mods

I had a PA 3200 single disc, lockup. I switched to a PA 4200 multi-disc lock-up. I have a toggle switch mounted on the console that I use to control the lock-up myself.

Highroller said:

Jim

what does locking up the converter actually do.. and when do you lock it up?? thanks for everything guys..

Im just paranoid before I shell out all this cash...

I guess I am interested in the lock up schedule that I should generally use for my car!!

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I can't answer that in technical terms, but in layman's terms, it creates a hard lock of the transmission input to the output so there is no slip. This eliminates the approximate 7 percent slip you get with a non-locking torque converter and improves your gas mileage. Normally the converter only locks up in highway cruise, I believe. With my manual valve body and converter toggle switch, on the drag strip, I can lock up in any gear I want and pick up a few 10ths.

A locking converter also reduces your tranny temps because there's no slippage when it's locked-up. When driving very easy with the stock lock-up schedule, you should feel it lock at 25 mph (in 3rd gear) ... not just when you're on the highway. When you lay into your car hard it unlocks then locks-up again when you ease off the throttle or around 90 mph or so if you stay on it hard ... I forget the exact speed, but 90 is close from what I recall. I can't tell you which one is best, but I would definately go with a lock-up converter.