Maybe you could make something better than the VH45 "spider" intake manifold.
Perhaps with some practice you can make something like this dual plenum:
http://www.zparts.com/showcase....html
I think some of the earlier DOHC nissans have a lot of potential locked up in the intake manifold like the KA24DE and VH45DE. I mean look at the VG30DE in the versus the gen 1 VQ30DE in the maxima. Both are 3L and the VG makes 222HP while the VQ only makes 190HP. Okay so you may say, he bore/stroke numbers are different and the VG has VTC so thats whats the reason behind the power difference. Right? Well then look at the gen2 VQ30 versus the Gen 1... we're back to around 220HP with the major change being the intake manifold.
I'm not sure how discrete the 5 parts are, but maybe they could be.
1. Lower IM (one piece for cheapness, but two seperate internal chambers for decreased turbulence)2. Upper left IM3. Upper right IM4 & 5 Thottles and linkage.
Maybe you could design something trick and powerful that would (at least come closer to) clear the stock hoods of a Z32 or S13 when swapped in.
A lot of work but could be worth it