6.2l 4.02x3.74 379" un ported factory head's, sheet metal intake 105MM TB, free Boss injectors, short tube headers, factory lift .510 lift cams shorter duration, 10.1:1 CR factory twin plugs stayed. 2003 crown Vic PCM used with CNC'd cam timing sprocket 4.6l sensors retained with new harness. PCM calibrated for engine size. 6500RPM 521.4HP all together I paid a little under 4K. 5.0l 3.63x3.65 302" MMR intake, 86MM TB, boss injectors, factory PCM stock 11:1 CR, stock un ported heads, forged rotating kit, stage 2 cams 7450RPM 541.2HP sole intention was to use this 5.0l in a track car for use here in Delaware. the 6.2l was my engine built for use in my 03 crown Vic that I shortened. a street driven car only. my tuner decided to try one spark plug he un plugged the wire, the engine ran fine two plugs were used no gains in power.