The A/F ratio starts out at about 14.7:1 because that's where its supposed to be in closed loop. It won't switch to the richer "Power Enrichment" mode A/F ratio until the TPS sensor reaches a certain level.... e.g. when you floor it. Don't be concerned with the 15:1 before they hit the throttle.

As far as the "brown" smoke.... did it do this on all the pulls? How long has it been since the car has been run hard? A buddy of mine had his car off the road for a while for some mods, and the first pass at the track, it blew a 30-ft cloud of orange/brown rust out the back of the exhaust:

http://cjcfo.fbody.com/members/injun...F/DCP02505.jpg

 

To see the charts, click the link in my sig, page 5.

The cloud was worst of the first pull, not so bad on the second. But it's all been apart recently and the motor has less the 5k miles on it.

 

The heads will allow the HP #'s to climb until 6000 RPM on a 383. The car will PULL higher but the HP #'s will be done by 6000 RPM on a 383 with a hyd roller. If the #'s are peaking before this, tuning might possibly get the #'s to continue to climb.

If you look at some dyno charts for 383's with my LT1 heads, you will see all of them peak at 6000 RPM or so with a hyd roller unless the cam specs or tuning is the hold up.

Lloyd Elliott
972-617-5671
Eportworks.com