Found what I was looking for. So my early measurements were
Cummins R2.8/NV4500/LT230 (with rakeway stubby + Xbrake) was around 62" total (including adapters from crank pulley to Xbrake/Pbrake)
Chevrolet LQ9/NV4500/LT230 (with rakeway stubby + Xbrake) was around 56" total (including adapters from crank pulley to Xbrake/Pbrake)
R2.8 (25.1") + adapter (1") + Nv4500 (18.8") + adapter (1") + LT230 stubby (16") so that puts you at 62"
LQ9 (20.25) + Nv4500 (18.8") + adapter (1") + LT230 stubby (16") so that puts you at 56.05"
So yes now I remember that the R2.8 with this combo is a bit too long and absolutely if you are saying that the R2.8 cannot sit as far forward as the B30. Since you have your eyes on the real deal
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