I've got Trick Flow heads, a CC XE274H cam, 1.6 full rollers and hedman shorty hedders. The hedders dump into a poorly customized y-pipe which is connected to a flowmaster muffler. The car runs very rich. I set base timing at 8* (wire disconnected) and I have no hint of any knock - even with the cheap gas. Should I bump the timing up more? What base timing is recommended for the stock cars? I have aluminum heads, so I understand I should be able to take more timing - is this correct?

The car runs hard at times - but when it's cold...it stumbles (missing) around a lot and stalls when put into gear. I'm also only getting around 12mpg.

 

anyone?

 

91,

Have you checked the mixture with a sniffer? Timing will surely affect combustion efficiency, but if it is THAT rich, you may have an O² sensor problem or excessive fuel pressure, injector leakage, etc.