First, you don't need a wide band O2 sensor, but it is sure nice.
A wide band will get you a simple result, at a cost, but you can get close and safe readings with a standard Ford o2 sensor hooked up to welded into a 1/8" bung. The extra money you've saved can be spent of checking exhast back pressure. If you can reduce it to 4 or 3.5 psi at 5000 rpm, your laughing.
Just a narrow band O2 sensor with a multi meter will do the trick. Pick up the look up table of air fuel to voltage readings for our current oxygenated gasoline, and ensure that you have a passenger to fetch the readings when you drive a predefined route with the right mixture of steep road gradiants and a 1/8 th mile flat section you can use as a standing start to wide open throttle acceleration zone. You are trying to elimninate a very rich situation when you drive under wide open throttle, and then trying to eliminate excessively lean conditions when you are cruising around. The stock power valve channel sizes are huge, so you need to copy wsa111's work, and shell out the sum for brass correction PVCR jets. 55 to 59 thou is too rich, but if you drop back to a smaller Power valve channel restriction, you'll be able to make a richer than 14.7:1 air fuel ratio under wide open throttle. Then you can concentrate on getting enough fuel pressure to allow a 6.5"Hg power valve to do its job. From there, you can work on the squirters which give the right low end response. Most of you work won't need the air fuel ratios, but just a quick check that the O2 sensor isn't running into a too rich or too lean zone
Second, relating the the 150 hp flywheel power figure you'd like. If you don't have a direct mount 2-bbl, you'll basically be limited to 150 flywheel hp with the cam you have now.
To get there, a standard Clay Smith cam profile will get you a nice streetable engine with good power, and it'll suit your driving style.
Third, if you want more with a log head, and you want to push for the very best in power, then you'll need a custom ground shaft with NASCAR Winston Cup restrictor-plate lobe profiles to help compensate for the log head and its two- barrel carb. These designs
a) reduce seat time to bleed cylinder pressure at low engine speed
b) bolster intake flow as revs climb to offset a restrictive intake tract.
The principal is the Kenneth Duckworth restriction plate era which first started with a technical brief delivered to FISA in 1980 by Cosworth Engineering. It wasn't acted on, but back then they calulated how much peak hp you could make by restricting air intake size, and via jetting. Answer was a 53 mm restrictor plate that gave a 183 cube engine no more than 500 hp, with 27 cc per second fuel flow(One 1620 cc/min jet really). On 650hp NASCAR engines, they use four hole 7/8" to 1.03125" restrictor plates depending on the year.(See
http://www.jayski.com/stats/restrictor.htm) The first plate was actually started with GM in the Pontiac Firebird 400 in production engines with a lead tab in the venturis back in the late sixtees to fit in with a corporate edict on not having ltess han 10 punds or car per gross hp. In 1971, NASCAR started mandating carb size restrictions, although they were technicslly mandated it in other ways since 1966. 1988, it came in force as a plate. In WRC racing since about 2000, for 122 cube turbo engines, they use a 35 mm restricter plate for 300 hp
Read more about the concept on :
http://auto.howstuffworks.com/auto-raci ... afety4.htm
If you read
http://www.hotrod.com/techarticles/engi ... z1erjHlSqZ, then you can see that its not outside the bounds of possiblity that the 350 cfm carb can flow up to 245 hp if the engine has a longer inlet duration NASCAR style camshaft which controls exhast lift and duration to ensure the peak power band is elevated. Argentinas TC racers with 2-barrel SP 221 heads on 183 cube engines do 340 hp at about 7500 rpm with just a 2-bbl 38 mm Weber carb, using the same cam technolgy, and about 350 cfm of car flow.
If you really want to know, a 460 engine can make a 500 cfm Holley due 420 hp using the same concept
