I have dyno charts for most of my modifications, including tunes. At times I changed 2 things at once, for instance the downpipes and teflon Y pipe. I've run at the drag strip with the 178 ASP pulley and stacked. (178 and 65mm Code 3) I may throw on the Code 3 for a stacked dyno pull for the fun of it. The drag strip, for me, says stacked is .01 faster. I'll let others guess why. I can tell you it pulled like crazy in 1rst and 2nd but laid down in 3rd. something terrible. Again, others can speculate if they desire. The 16hp for the manifolds is a fact on my car, in my weather, which varies very little. So you can expect gains from the modded manifolds.

Les