I just picked up this D4-7U dozer with a Holt blade and a Turbocharger.  It is the first D4-7U I have seen with a turbo and the installation looks really professional.
Based on the serial number it was made in 1951.

https://1drv.ms/u/s!AnopHm03RZURgd8uS0xTHzdnrmgTVQ?e=VpxCAw

Congrats-do you have a video of it running? I'd like to hear the turbo. I tried the link, but would not open.

bernie

I will try to post a video, its pretty bad though. The turbo is barely audible, but I suspect you may hear it if she was pushing a blade full of dirt.

Here is the video...
D4-7U

Hi, ol coyote.
Nice catch. Congratulations.

I can't help thinking though that the blade was made for people who are scared of work - it sure izza long way out in front of you.

Just my 0.02.

Hello Deas - That is funny....I was thinking the blade was set waaaay out there so the turbo would not suck it into the engine.

Hi, ol coyote.
That sure would be one POWERFUL sucker of a turbo.

Thanks for sharing the photos.

Just my 0.02.

i wonder how much power gain mind you they only had 50hp at factory spec.

Depends on the rack setting, sometimes a turbo can be added for higher elevations, if fuel is set higher up to 20 more horsepower could be added. Some D315 power unit's with just higher rpm put out 90 hp.

I finally got a chance to adjust the steering clutches and she steers and pushes great. She can definitely spin the tracks.
Here is a video of her pushing some stumps, trying to get her warmed up for an oil change.
1drv.ms/v/s!AnopHm03RZURgd83uZ-tZ3lX8E7naQ?e=0R2dhE

Here is a video of her idling, I could listen to that music all day.
1drv.ms/v/s!AnopHm03RZURgd828Cba7ehcFGMjxQ?e=aEiypB

I still need to change the oil in the transmission and finals, adjust the pony starter pinion springs and then she should be good to go.