serious race head??... my plan was to take them to a shop to be hot tanked, and gone over and to see exactly what I have.. then put them on my 84 k20 pick up... has a 383 stock heads flat tops, with comp cams xtreme energy, lift .520/.523 duration 274/286, headers, holley 670 avenger...my question would be, could I put these on this motor, and see an improvement? and still use 89 octane? is there such thing as too much head?? haha