I've read posts in the past regarding which 8 3/4 center sections are better and it raised a question. Were the various centers (741, 742, 489) specific to certain years or were there years where any two or even all three could have been installed at the factory? If any two or all three could have been installed in any specific year or model car, was there a determining factor as to which one would have been installed?

741 and 742 came first then the 489 in 1969 (?).

I think the 489 replaced the 742 when it became available.

741 seemed to end up in light cars or low horsepower cars. I see them in 318 station wagons and a-bodies.

the strength/bearing thing is BS. There are design issues with each case/gear set.

The 741 is a very capable piece.

Ring deflection is the biggest problem when HP goes up. Caps breaking and distorting which isn't significantly different from case to case.

It's one of the biggest red herring in the mopar world... JMO

It really doesn't matter much either way since there are far fewer gear choices for the 741.

741's and the other small pinion carriers were in max wedge cars

1 have a 741 3.91 SG that came out of a '69 340 Dart. I used it in my red car shen I was spraying it. Never broke it.

All three carriers where installed in all cars using 8 3/4 housing in 1969, the 489 case was another mid year parts change that Mopar factories did for some reason not divulge to us racers and consumers
Before that mid year change only the 741 and 742 cases where used from around 1961

which is better the clutch type or cone type in the limited slip.

I had a '69 Dart Swinger factory 340 car that also came with a 741 sure grip. The clutch sure grips are the ones to look for.

Dana Corp. clutch type due to them being rebuildable

CAB it’s no mystery why they dumped the 742 and went to the 489. The crush sleeve saves assembly time.
The 741 and 489 take the same pinion seal. The 742 pinion seal has a much bigger outer diameter and that’s because the pinion bearings are larger diameter.

I've seen one 489 pinion shaft twisted in two pieces by a off road guy who had replaced the 9 1/4 rear end in his 4x4 Ramcharger with the 8 3/4 out of a late model C body and had the pinion angle pointed up past the alignment with the drive shaft
I've broken and cracked the teeth on all three 8 3/4 ring gears, not so on a Dana 60 yet

Uh-uh. MW cars got the 1 3/4" pinion either 742 or 985 housings.

Every 8 3/4" rear failure I've seen has been either teeth broken off the ring gear (which damages the pinion teeth), or the axles twisting at the splines. I've never seen a pinion shaft twist in half on any of the 741, 742 or 489 cases.

It's rare but it can happen