Slant 6 stroker?

Iron log heats the intake manifold since they are bolted together. Just removing the heat flapper door helps a LITTLE but not enough for Hi Performance NA or TURBO.

But you can machine the iron center section down and POOF, turbo exhaust manifold.

Plus, a little power gain in port timing by matching the firing order into 3 + 3. Not a lot but when you are talking a little free power here and there......

On the Iron log we split years ago and brazed a steel pipe on each set of 3 cylinders it was OK until we started running 5500 RPM for over 1 minute and the whole log was glowing bright cherry red. The 2 J pipes all the way to the turbo was dark cherry red too.
Or do like I did and just block off the hot air to the intake altogether. There's still some heat transfer, but nowhere near with the the two still mated.