Monch

don't know for sure, but if the timing were off, as in too advanced, and your running 87, and factoring in the new compression ratio you have with the new heads i'd say there is definately a chance of something going bad.

your car will make more power when its running on 91+. also, it may take a week or so for the computer to re-adjust itself to the new setup.

if you haven't already, take it down to the nearest gas station and top it off with premium.

anyway, congrats on the swap!

01GT

mustangs don't like that cheap gas you have to put premium in them. As for the hissing you just need to let them break themselves in. Go ahead and stopm on it.

GT99GT

thats absolutly wrong, mustang actually do like cheap gas, once u change your timing or do major performance upgrades, then you can use 91 , so if thats what u meant than ur right, but stock or nearly stock mustangs should be using 87-89, no more than that because its actually worst for the engine

Monty

The noise was a loose cam gear bolt.( a redneck let me know right away.....

Well it ran like a dream for 2 days and i just snaped my timing chain[:@].
So no stang untill tuesday.....NO BUENO!!!!!!!!!!!!!!!