With D type cams, is there enough vacuum for the brake booster to be effective or should a vacuum pump be installed

 

If the cams are coming from an established tuning company, they should know. Incidentally D type cams range from standard with a few degrees extra duration to the WAD, which are still not excessively wild.

 

A few more thoughts:

Rob Beere is probably the most knowledgeable person on Jaguar cams. You can find him via Google.

There are E types with D type heads and engines. I don't recall them requiring a vacuum pump.

As you've posted on this subforum, I guess the engine is going into a saloon. Even a Mk2 is a fair bit heavier than a D type, which might influence the torque Vs power compromise.