you will probrably want to stay with autolite 24's gapped to around .032. Stock plugs are 25's at .054. I was told that the 23's may be to cold for light load conditions on the motor. Ex. low rpm driving and cruising. // go with a 70mm TB and if you are actually going to run the 11lb. pulley make sure you keep your rpms below 5800. The maximum repeatable rpm's of the blower bearings are about 36,000 rpms. There's a place called 928 motorsports and speacialize in modifiyng powerdynes for V8 porsche 928's. Goto 928Motorsports.com and they have all the info you need on the limits of powerdynes and how to improve them.