I noticed today that my car's power seemed very low, and acceleration was not very fast. I listened to the exhaust and it sounds like I have a miss. I have a split pipe exhaust, and only one side is wet with gas, so I imagine that the miss is on that side. I'm thinking I should pull the plugs one by one and see if I can locate the miss.
I was having trouble with the carb running rich so I adjusted last night. It performed much better as well as started right away without giving it gas. I'm wondering now if it might be a little lean.
Is there anything else I should test to see what's wrong with my vehicle?

You sure its gas and not coolant?Could be a blown head gasket or worse.SB 400s dont like to be overheated and the block can crack.You have 400 heads?If not you make sure the steem holes were drilled through the heads?

well I checked the spark plugs and they were carbon fouled. I changed the worst two and started it up. It doesn't seem to miss anymore, but there was white smoke at startup, which makes me think that there could be a bad valve stem or a bad head gasket. The smoke only came from the drivers side pipe. There wasn't much white smoke though. The coolent temps have stayed good, so it hasn't been overheated as far as I know. I haven't seen temperatures above 200 while driving it. It hasn't been driven hard or far since it started acting funny.

If these cylinders were next to each other and it happens again do a compretion test.The gasket could go between the cylinders.

No, the cylinders were on opposite sides of the motor. The plugs were fouled identically on both sides of the block, as in the same spots were fouled the same. I think its a result of it having run pig rich for awhile before I got it and retuned the carb. I got 6 of 8 new plugs in (gonna take off the headers tomorrow morning to get the last two), and it woke up. It drives much better, revs much faster, and makes a ton more power now. I am going to get the last two tomorrow, I imagine that they are still costing it some power.

Took the car out for a short drive, and it ran great till at the end when I stopped at a gas station. It puffed out a bit of white smoke while idling. I imagine that there is some sort of leak going on somewhere. I guess possibly a small head gasket leak. I'll have to look into fixing it. The power is still great, although I didn't give it much gas. I also need to put a tach on it and adjust the idle speed 100%.

Perhaps I need a new thread about the white smoke.