94 Mustang Cobra

my car is burning oil, thinking it may be the valve in the head maybe thats what im hopeing it is, did a cylinder check on all 8... 1-7 were anywhere from 130 to 140 but #8 was 110 also i have oil in my intake tube all the way down to the Mass air flow, im hopeing its just the heads if its rings or something im gonna just start building that 408 i always wanted

thanks for your time and help
Ron