Increasing lift is not practical I would think. Duration increases are limited as well I suspect to less than eighteen degrees on either side of TDC. This is because the engine becomes an interference engine when the cam is only eighteen degrees off. My logic may be fuzzy here so make allowances.

As the revs come up floating valves may also be another problem but with good valve springs and the engine rpm not elevated much it may not be an issue.

I would try to locate a company that has actually got the specs of the redesign of the original cam profile and has proven it in service. Not start from scratch.

The suggestion to contact colt cams is the way to go in my opinion as well. If they post their reprofile changes it would be nice if you could post them on site and the claimed difference. Most engines out there intake fuel through the intake valve.

Unfortunatly these old indirect diesel intake fuel from the precombustion chamber so I would thing there may be something to gain but not as much as on a typical gas engine. In the final anyalisis what do I know though? Colt cams claims might blow me out of the water.

Now the above said the later cams over the earlier are a higher horsepower gain type I believe in the 123 blocks. I guess the issue is if the factory did take it as far as practical.