Is a 1976 A999 transmission the same as or comparable to a 904 torqueflite?

A999 is lockup, and some have a lower 1st gear ratio.

All A9xx series trans are related. the 904 is the /6 spec. the 998 the 318 spec. the 999 the 360 spec version. All versions can have a lock up converter.

As the number gets bigger the capacity gets greater.

So an A999 is the most beefed up production A904 variant available.

A999 would have the 5 disc front clutch.

from "HP mopar" magazine: the best one is one from a 75 to 79 cordoba/coronet behind a 360 & it had a 5 clutch drum & a better pump compared to earlier ones & to avoid a lockup unit but I thought the LU's came later??? here is a link for some more info & I would Google it also. http://mmerlinn.com/catalog/lil_sis_4/tf_9nr/tf9nr010.htm EDIT found a note: LU started in 1978/& it is 26 splines/smooth end on tip of input shaft as opposed to splined all the way

My Diplomat "AHB" Police packages came with A999 with lockup, but went into lockup later (seems to be about 10mph later), five clutches with HD parts, wide ratio. Which is pretty much what GuitarJones and RapidRobert wrote. Good trans really.

The A-999 was introduced in '74, lockup didn't arrive until '78 and the lower gearset until '80.

I have a low gear set lockup Frankenstein 904 behind a Magnum stroker. It has stuff sourced from aftermarket, 32RE and A999 gearboxes. My buddy that helped me set it up said he'd call it a "34RE".

I've been pretty rough on it, though no passes yet, and haven't had any problems. It doesn't spin on the 2-3 upshift with the converter locked, that said, lockup is a bit scary if you're not expecting it. Not sure if I'd go that route for a car that is routinely drag raced as I'd fear for the input shaft. It is great for my purposes and when cruising, the lockup drops engine speed 300-500 RPM. A gear vendors in next in the project plan.

I control it with an adjustable pressure switch in the governor test port to close the circuit (lockup) at 52MPH and an adjustable vac switch to open the circuit (unlock) when you romp on it. I use a relay to unlock when I step on the brake. I've also got the governor tweaked to not upshift until a little over 5K at WOT (hence the need for the adjustable pressure switch).

Fortunately, the lock up is hydraulic actuated, so it's easy to delay or eliminate. Are LU's low stall?

I do remember the early hydraulic lock up converters. Some of them came on pretty early and you could really feel it. Seems to me we changed the spring in the hydraulic ones to change when it came in but its been a long time since I worked on a hydraulic one. Most of the ones I worked with were the electronic lock-up as I worked at a Dodge dealer from 1986 to 2011. I don't remember what year they started with the electronic lock up though but most of the ones I worked on were electronic lock up ? Ron

First year for the electronic lockup was '86.