How does the P3 and P4 plug compare then? Never really tuned with plugs so does one give more top end power than another or just a steadier idle??? Got to say, managed to get the engine going this weekend. Had a bit of trouble in qualifying getting it tuned (idle dropped off loads, and it's still new), but it was still running rich on the bottom by a lot. In the finals i managed to bump 3 times and would have for a 4th if it wasn't for a few over enthusiastic drivers. Engine is smooth but it does lack topend on the longer straights over here in the UK compared to Nova and RB engines. Was running a HN 2047 and it was extremely smooth and seems to be the pipe of choice over here but i would like to do a back to back test against the AE 2035.