Wasn't sure whether to add this here or put it under the what I did this weekend thread. Seems it would be most appropriate here. This weekend I went to the pick your part place in Oceanside and snagged a 280ZX dizzy to replace my Petronix/standard dizzy. I too had the 4000 RPM stall and was hoping this would fix it. At 4K, it seemed like the ignition was cutting out and I could actually get a gas smell, so I was thinking it was an ignition issue. The change out was pretty easy since I already had the Petronix. I pulled the old dizzy and mount, noted the rotor location (cylinder 2) and installed the new 280zx dizzy and mount and started the cabling with rotor location being cylinder number 2. This worked great, started right up. Odd thing was the RPM's would go up much higher than my other dizzy. Had to break out the Unisyn and lower idle speed. The thing that is odd here is if my earlier dizzy was optimized, and I think it was, why would a new dizzy bring the RPM's higher? Anyway, I have the dizzy dialed in and I love how it runs. No more 4K stall and maybe just me, but car seems much smoother. I will keep the old dizzy just in case, but for now, it seems like a nice change. So for my Yellow '71 240 Z, I am now running a 280 alternator and 280 dizzy on a 260 motor. Talk about a hybrid.