Yes, for Nova's at least....

T-3 Headlights
 

From what I have learned over the years, Power Beams started June of 70.

Mike

Power Beams on my 1970 Nova first week of April. They have the letters GM in a little circle at the bottom. I believe these are original assembly line, and, at a local car show I saw these same Power Beams on a 1969 Camaro.

I might be missing something but those from lectric limited were discontinued a few years ago. Then some time later someone else was advertising them. Wagner was making them for lectric limited but again thought that was stopped.
I've taken originals and put silicone around the terminals to help keep them sealed. Don't know if it works but so far so good. Our 01B 68 still has the originals in with date stamps showing made in Nov. 67.

I bought a couple of sets around 2004-05 when they first came out. The link I provided shows they are currently selling them.

The link shows them in picture only I believe. Sometime around 2015 is when Lectric Limited supply ran out (made by Wagner) and other houses selling them like Rick's and others show them discontinued. I completed a quick check and could not find them for sale at Lectric Limited but maybe I'm missing something. PacecarJeff is adversting lamps without the DOT so would assume these are different since what Lectric Limites was selling had the DOT. I purchased a set just to review power and how accurate to originals.

The parts place has reproduced them. I bought a set and they look great. Much less expensive than Latric limited too.

I'm not sure of the exact transition week, but I've documented Deuces built in 05D, 06A and 06B with Power Beams - not to say that some may still have T3's though....

Didn't Norwood do a video on how to modify those and use a bulb in them?

modify a sealed beam?