3rd rail/sunset big boy- variations and comparisons to mth/lionel/etc

I have a 3rd real big boy with tmcc. Works well. detailing is fantastic.  I can run it on 072, but it has such a huge overhang it would run better on 081 or even 090 or 099.

I use Atlas 3 rail track.

I would keep the Sunset 3rd rail Big Boy tmcc and go electric rr conversion . And Sunset big boy is a very heavy engine  15-20lbs I'm guessing. You won't be disappointed with Sunset 3rd rail.

The Sunset/3rd Rail Union Pacific 4000 Class 4-8-8-4 is the most accurate model on the market, hands down. They offered #4023 AND #4024, both with TMCC RS4. They run beautifully and sound great, except for the whistle, which is the "standard Lionel licensed" articulated sound package which is the N&W hooter whistle. I acquired a "UP whistle" sound chip for a Challenger, so that my Sunset/3rd Rail #4023 correctly sounds like a UP articulated.

The MTH UP 4000 class model, has excellent sounds and is correct for the "later" 1940's modified model.

I have both models and they both operate flawlessly.

The Lionel Legacy version is very nice, but has the wrong whistle for UP big steam locomotives, i.e. 4-8-4s, 4-6-6-4s, and 4-8-8-4s.

thanks for the info!

electric rr conversion-???

I've seen the 4023 and 4024 with tmcc, what about a 4007 version? tmcc? detail level?

Electric rr is for tmcc.