well the shaker hood is better from the point of view of bringing cold air into the engine from above the hood , the ralley hood will bring in some cold air with the plates removed but the air cleaner is not sealed to the hood . We did some testing with a super stock Hemi Cuda years ago & tuned the engine on the dyno & we make a good power increase tuning it & we also tested spark plugs looking for extra power & proved that the more expensive the spark plug the more power was lost & we also found that as soon as we put the shaker scoop back on the engine all the power gains that were realised with tuning had to be reset back to where we had them due to the resticted air flow through the shaker . In the engine book they list a large area for the minimum opening for a hood scoop & the big 6 Pack scoops on the 69 Runners were approx correct to feed the big Mopar engines & the Shaker scoops are definatly too small to fed a dual quad Hemi or a 6 Pack properly
