Yea, the EFI cam LSA's are in the 112 and up range. The Z303 I've got in my 331 has a 112 LSA, it's got a wicked lope at idle, but it's pretty efficient when it comes to fuel economy. Mileage is in the 16 MPG range cruising on the highway at 3500 rpms in my Comet, it was about the same when I had this motor in my 89 Ranger with similar gearing. It's completely comfortable running around town in stop and go driving. I've also run a B303 (same 112 LSA) in a mild 302 in my Ranger, it too had a healthy lobe at idle and was likewise fine in everyday driving, I don't recall the fuel mileage though, but it didn't break the bank either, even with my heavy foot.
You get 16 mpg and I get 21+ .... you must be right You are obviously making the best use of your fuel - much better than I. At low speeds part of the exhaust is actually pushed into the intake runner - that cauases diluted intake charges. You need a richer mixture to make up for it. At around peak torque the exhaust gasses pull part of the intake charge out the exhaust leaving less fuel and air in the cylinder. This again requires a richer mixture to keep the power there. All automotive cams have an overlap - a time when the exhaust and intake are both open - even the stock cams, but once you get that overlap wide enough to cause a lope it has detrimental effects on the mileage of the car.
16 MPG at 3500 rpms cruising down the freeway is VERY efficient. Remember this is with no overdrive thru a C-4, 3.50 gearing and doing 75-80 mph. You're getting 21 mpg at what rpm and what speed ? And there's nothing rich about my carb jetting over what it would be with a smaller overlapped cam. Even the stock settings would then be overly rich using your analogy I guess you've forgotten about EGR systems ? There's less exhaust gas mixed in the intake charge with a wide overlapped cam(much less the Z303) than there is mixed in there in your average everday ordinary EGR system today.
How are you planning on using the car, strictly street, some track time, a lot of track time? Be aware of the Edelbrock cams metioned earlier, Ebrock does not grind or even design their own cams. All repackaged cams, those made by actual cam grinders but sold by other companies, are made by one of two companies. You'll see Summit, Jegs, and others selling cams with the same specs as Edelbrocks but for half the price. They all come from the same places, it's just that Edelbrock gouges you. Buy from where you get the best price. I've heard a lot of good things about Delta over the years. Comp Cams has a cam selection software on their web site you can play with. Of course it only recommends Comp grinds and the hp figures are pretty optimistic. That's how I picked my current cam and I found it used on another forum for $120 shipped. A lotof guys get good results just running a stock HO cam with 1.7:1 rockers. And guys, no one designs a cam to have a specific LSA. LSA is just a result of the chosen lift, intensity, duration, and EVC/IVO event.
