OK, just re-read the entire thread.
One thing that comes to mind is the use of high-test fuel. Why are you using this? Octane is a measure only of the speed of the ignition of the fuel; nothing else. Higher octane fuel ignites SLOWER than lower octane, thus helping to avoid detonation in high compression engines. It also requires more spark for starting. There is absolutely NO more energy in high-test than in regular, and depending on how much deathanol has been added to increase the octane, maybe significantly LESS energy. At best, the use of this fuel in a stock 235 is a waste of money.
I think regular fuel will help the cold start problem.
In the meantime (prior to burning the high-test out of the tank); it would be interesting to know the condition of a plug immediately after you tried and failed to start the engine. A wet plug might indicate poor ignition, a dry plug might indicate no fuel.
Another test we have used to prove or disprove poor ignition is the use of a second battery. Hook one battery only to the starter, and the second battery to the ignition system. The starter will lower ignition voltage. A second, but not quite so revealing method, would be to have your truck battery fully charged, and simply add a fully charged "jumper" battery with jumper cables. This way, the starter will only drop the voltage by maybe half of what would be dropped by using the single battery.
And I would agree completely with Bill, throwing modifications at a problem only introduces an additional level of uncertainty; fix the problem first.
And while it may be entirely coincidental, 90 plus percent of customers who call us with "carburetor" problems on older vehicles have an electronic conversion in their distributor??? I personally go the other way. My own very high performance vehicle has the HEI removed, and a genuine GM points and condensor distributor installed. Yes, it does require me to occasionally change points, condensor, and plugs; but it has not failed yet.
Jon.
