Cranking pressure is a function of static compression ratio, cam size, cam timing, and altitude, so it could be right on the money for your combination. Whether it is good or bad really depends on the sum of your parts and your performance goal. Since the general rule of thumb is 180 psi as a max for pump gas, you're giving up some potential power. This means you may be able to back down some of the octane rating at the pump.
Checking plugs is a good start for diagnosing rich/lean conditions, but a meter is certainly a much better approach. Before spending $500-900 for a new carb, I'd suggest finding some one in your area that can do some dyno tuning and exhaust analysis. You may not be as lean as you think since you usually have to put some load and miles on a plug to get a clear idnicator of what the engine wants. Especially ifi you aren't turning it over 4500 rpm and you haven't changed the step up springs. Most places that check diesal trucks have this capability and even if you pay $100 or so to do it, it is cheaper than buying a new carb. Might also give you some insight into how much ignition advance you need too.
