Custom obviously. The BJ's manifold is nice for the price and has been tested and proven on n/a setups. It would be interesting to see how my BMC Race manifold would do on an n/a setup. Its got the right runner lengths, very well formed trumpets inside, Nice plenum design and large plenum. The builder of it built it based on my revs which was 9700-10,000, so for a nice high comp ve on kelfords id bet it would do pretty well, especially over that KS manifold and the stock manifold, and the Excessive plenum on n1 runners.
It has all the necessary key elements to work very well. Only downfall on it is the runners are not perfectly straight and have a slight curve to them but they angle into the head at the same angle as the port and the curve in the runners is very smooth so i doubt it will matter much. Also the runners are quite large.