so i have found that my miss is actually cyl. 5 & 6 having low compression(100-105) while all others are at 150-160, the vaccum guage jumps between 16-18 ish inches, valve problem maybe? maybe the timing chain jumped a tooth? any suggestions or comments would be a great help, oh and its a 1995 3.4 from a 95 bird, 57,000 ish miles

 

Id back the back valves off first.

If it was a timing problem, it would act differently.