Maybe this falls into the Misc category, but what about forced induction. I am doing a turbo build and there are quite a few parts associated with it. Maybe you handle it like your transmission page, have a drop down for nitrous, supercharger, and turbo?
You have done a service to a lot of people and I thank you for it.
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'89 IROC-Z Turbo 3.8 5SPD
LS1 Brakes|Wilwood Prop Valve|LS1 Master Cylinder|Aluminum Driveshaft|LS1 3.42 Rearend|Adj PHB|Adj LCA|LCARB|Koni Struts|Koni Shocks|Adj Caster/Camber Plates|STB|10 Spoke SS Wheels|PHB Relo Kit|Adj TA|SFC|ARAP Based Prom|B&M Short Shifter|Underdrive Pullies|SMOG!|AIR!|Rag Joint!|Magnaflow|Ported Plenum|Misc Stuff