Ok I have been dealing with a problem that, because of the warm days has gotten worse, or more likely I am now driving it when its hot. The car starts runs fine until the temp gets to 200 then I start getting some misses on occassion. At about 210-220 it like its hitting a rev limiter and poofs out the back. Its not a back fire because it sure ain;t loud. If I turn the heater on and cool the car down below 200 the problem disappears. Happens at any speed. IF I am on the freeway and it starts I can get at current throttle and its fine, but If I go up hill or give it gas it acts like it has noting to give, and stumbles. Heres what I currently got: 5.0 - 34k miles on rebuild motor. unfortunately the cobra cam was replaced with the explorer cam by Ford. comp 900 distributer MBI Promaster coil 9mm wires edlerbock rpm manifold edlebrock 1405 carb edlebrock victjr fuel pump (first changed from standard edlebrock pump I though it was vapor locking) Holley regulator A/C Timing 10 degrees at 800 rpm 34 at 3,500 vacuum bounces between 16.5-17.5 at 800 rpm increases to almost 2 in. when in drive between 14-16. idle in gear 660-690. What they heck can I check?