You think a 383 is going to get me better mileage than a 350? I find that hard to belive. I live in mainly flat area, but do use the car in town a lot, so going for the bigger engine might be a good idea. But I never even thought of building a 383, surely the longer stroke will increase my comp ratio and need higher RPMs to run well, or isn't that true? I haven't spent much time on 383s yet. And I don't know where to have cam and crank aligned either, I live in Germany, where many people just buy a different car and not very many fiddle around with things, so there isn't such a thing as a "local machine shop". And I asked about having my crankshaft balanced and it would have cost around 600 bucks, and that's going a bit far (but I have only asked at one place so far).
How much would you expect a bluprinted block to cost? Is that better and straighter than buying a new one?
I've asked at Holley and Edelbrock and they say with a well set FI you can gain about 12-15% in mileage over a well tuned carb, I guess that would be the single most important thing to do. I have been fiddling with my carb a bit (rods and jets) and it sometimes does seem to make a difference, but not really in mileage. I guess I'll just wait for a few more answers and start looking things out, which might fit my plans...
Just another idea: can a BBC make the same milage as an SBC? If all of you say the bigger the better, but there's a limit somewhere. But I probably couldn't fit a BB into the engine comp of my van anyway.
Let's see how far this project goes...