440 total timing

It definately sounds like there is an issue. The Fluidamper could be slightly off, I've seen the marks on them off 3-4* in one case. Always a good idea to verify and re-mark the TDC when it's being put together, regardless of brand of balancer. Also, what pistons are used for the "10.5:1" you have? A flat top with lose quench will like more timing than a dished piston with tight quench. I generally run (VERY general..each car/setup is diffferent) 38* with iron heads, 32-34 with aluminum modern chamber heads. Especially if they are pump gas engines. The fuel burns much faster, and in a well designed head/chamber/piston top combo, will not require as much timing to run well. Looking quick, I'd say part of the problem is the 750 carb. If it's a typical 4150, it really flows about 690 cfm wet (with fuel). More importantly, the air bleeds are sized for an engine that is smaller. You're able to pull a lot of air with your heads, and I think the carb is just sized too small in it's out-of-the-box form. a smaller carb youcan replace air bleeds on will really help the lean cruise. A larger carb, like a 850DP, or something like a Mighty Demon 825 or 850 will make tuning on the street much easier. Many guys only use CFMs to size a carb, but if you go to the Barry Grant site, you'll notice more than CFM or cubic inch, they use cam size too. For a street and strip engine, it's important to get things sized right, so you dont "give up" anything in any driving situation. Just a thought anyway...