I just put a TCI Streetfighter 2004r behind the 454 in my elky. Installed an ACC Performance Products Nightstalker lock up converter. It's advertised as a 2200-2800 stall. Feels more like 2800 than 2200. So far, I really like cruising down the Interstate with traffic flow at 2000-2200 rpm instead of 3200-3500.

The TCI tranny will lock up only in OD.....or, I can throw a switch and it will lock up in 2nd, 3rd, and OD. My question is what are the pros and cons of leaving the switch set for lock up in all gears except 1st?

Thanks in advance. I sure don't want to screw up my tranny right before driving to CB05.

Yes, you can setup for 2nd, 3rd, and OD lockup but, you have to pull the pan and install some parts to do it. Not difficult, though. Then you need to wire it. BTO has a kit. There are a number variations on how to wire the external switch(es).

Mine is setup for full manual control except for a switch on the brakes to disengage the clutch (comes in the BTO kit). I have a toggle on the dash that selects (2nd, 3rd, OD) (off) (OD only). I also have a turn signal stem mounted switch to disengage the clutch. I found that letting it lock uncontrolled in the lower gears makes for unusual and not pleasant shifts and is probably quite hard on the trans. I desengage at stop signs and when traffic slows, pretty much when the engine would lug with the TCC engaged. I re-engage after the car stabilizes at speed. I pretty much lock up all the time when conditions allow it.

Others use vacuum switches for more automatic operation. You'll probably get a wide variety of options thrown at you.

"....I found that letting it lock uncontrolled in the lower gears makes for unusual and not pleasant shifts and is probably quite hard on the trans....."

That's my question. Is letting it lock in 2nd and 3rd "bad" or "good" for the tranny?

The TCI tranny is all prewired for the two scenarios from the factory. I just mounted a switch under the dash that changes it from "lock in OD only" to "lock in 2nd, 3rd and OD".

My tranny guy said locked shifts from 3rd to OD under light throttle are harmless. Under heavy throttle isn't very good for the trans. I have only lock in 2nd on long or steep grades while towing.

Locking in the lower gears will lower the trans temp, a good thing, no harm to the trans. If you want to use the TCC around town, reaching for a switch under the dash is very awkward. I suggest installing a easy to reach fingertip switch of some kind, maybe mounted on the TS stem, as I have, or on the steering wheel. Or go with a vacuum switch for control (GM uses and has them). Do a search, there are several schemes around. Whatever way you go, you need to control the lockup. Not only to protect the trans but also to prevent lugging or detonation the engine.

Since you have a switch in, try driving around, you'll see why I say you need some means of control.

I have a 2004R in a 79 with a 3.07 rear and the lockup setup like you have. All my stuf is from BTO. I've tried manually locking it in 2nd and seeing what happens. A very hard and jerky shift into third is what. 3rd to 4th in lockup isen't nearly as bad unless your excellerating pretty quick.