CAT 1693 to Detroit 6v92?

The 6V92 is about 20 inches shorter than the 1693 and substantially wider, which means you probably have to drill the frame to relocate the motor and transmission mounts, alter the shifter linkage, lengthen the driveshaft, change the throttle linkage from one side of engine to the other, and likely a few other things that I can't think of at the moment.
So yeah, you need motor mounts.

I think the highest rating on a 6V92TA was around 360 hp.
For a toy the 6V92 will be okay, but if you plan on working it I hope you're not expecting it to be a powerhouse, even if it is hot rodded.

If you just want a noisy sucked out engine that puffs a lot of smoke and burns a lot of fuel, remove the turbo and turn it into a 6V92N.

 

If it was an 8V92TA I would be more enthused.

I've driven 5 or 6 8V92's, (that I remember), from 430 to 445 hp and I liked all of them.
They could be hard on fuel, but they all pulled well and were enjoyable to drive.
The DD 92 in this FL had a good tune up, was open to 2500 rpm and at 115,000 lbs would keep up to or pass a 400 Cummins going uphill at 80,000 lbs, but if I was loaded at 135,000 lbs a good running 400 Cummins on 5 axles would walk away.

Both these trucks walked a KT450 pulling a van on a long steady pull while grossing 110,000 lbs, the driver was not happy.


I don't care much for Freightliners, but I loved the 8V92's.

 

if this is a work truck I wouldn't use ether of them