With that cam and compression setup you got I'd go with the 1-7/8" primaries, but good luck finding something that fits decent without major modifications on those D150s.
With that cam and 10:1 compression I'd definitely go with the 1-7/8" primaries, TTI makes good stuff but yeah they're pricey - might also check Hooker or Hedman if you're on a budget and don't mind some fitment work.