I quoted 13s to compensate for the ring and valve seat/guide wear, which is to say there is probably quite a bit of for 10% variance in cranking compression. But a properly tuned Weiand hi ram set up is worth about 35HP over a single four barrel on a stock cam low compression engine, and 75 on strong street build. What is your fuel system as far as pump, line size, and pressure. What about the fuel tank and pickup? You really need a fuel pressure gauge where you can monitor it going down the track. I am going to back up and say when staring the initial tune on the center squirt carburetors that your probably lean out of the box with 76s, I'm thinking closer to 84s with the power valves blocked, but it may be right if they have four corner idling so you'll need to double check me on that. With your low compression outfit, get your timing set up for around 18 degrees initial and 20 degrees mechanical advance all in by 2800 for a staring point. If your going to run with mufflers, you really need to be running 3-1/2 inch exhaust. Cherry bomb makes them at this size for about 40 apiece but they won't be much quieter than straight headers, but there are several options available. For sound I am partial to Dyno-max or hooker Aero-chambers. You could put a high stall factory type torque converter in and go quicker with what you have now. But unless you or someone else just happens to have one just laying around but you are better off dollar wise to wait until you have decided on which heads and cam you are going with to custom order one. The majority of off the shelf performance torque converters are a compromise and aren't in the same category of what PTC, Ultimate, or Pro Torque can build for you.
