If my memory serves me right the were .110 in the hole. And these are the speedmaster aluminum heads.
0.110" deck height? Not good. Any quench is in the basement of the outhouse. Slants are even worse. Building an eengine today, I would be looking for a zero deck or possibly -0.005 deck height. The - indicates the piston is proud or above the deck. You want for a street engine that will run to 6500RPM a clearance between the piston and cylinder head quench area of 0.035" to 0.040" with the head gasket compressed. This aids mixture motion in the combustion chamber which aids quick and efficient burn.
Mixture motion can be two types;
1: swirl. This is similar to the water swirling when you flush the toilet. 2 valve heads tend to have this but port shape can promote or inhibit this swirl. SBF ports tend to inhibit swirl as the flow wants to dump out close to the cylinder center.
2: tumble. 4 valve heads tend to tumble, which is OK at lower RPM but becomes ineffective as the RPM increases. What happens is swirl is cancelled by one valve's flow wanting to swirl clockwise and the other counter clockwise.
Too much swirl can be counterproductive also, but generally more is better.
IMHO you need pistons with a taller compression height.
According to David Vizard's 128 formula for LSA selection and assuming 2.02" intake valves, you need a cam with the LSA at 103°. Yup, might tend to a bit rough idle. I would be looking at more like 265° to 270° advertised duration and lift around 0.525".
In your initial post you say the carb is an Edelbrock 1905. This would be an AVS2 650CFM manual choke item, with annular discharge boosters in the primary side. In a subsequent post you state the carb is a 1405. This carb is a Performer 600 CFM manual choke with conventional boosters.
So which carb are you using? Either are good carbs, contrary to what one poster states. The base calibrations are different and not explained by 50 CFM difference. The Performer 600 is an older design set up for non oxygenated fuels, no ethanol. The calibration is for a 14.7:1 cruise AFR or a lambda of 1. The AVS2 are calibrated to work with the oxygenated pump fuels today. Because of the ethanol content they require a "richer" calibration as read on an AFR guage. This AFR should read about 14.1:1 to obtain a lambda of 1.
Choice of the optimal carburetor depends. With your stated Airgap manifold, the AVS2 with annular boosters is the better choice due to the annular boosters providing better fuel atomization to the manifold. The Airgaps do not have the heat in the runners that regular manifolds have, so more atomized fuel works better. Now a conventional manifold with a fair bit of heat transfer work well with conventional boosters, but may tend to vapourize the fuel more in the port. This causes the fuel volume to expand greatly, which causes a less dense air and fuel mixture reaching the cylinder.
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