Weird Misfire

[Rod_Lei]

Hello again,
I've got an 89 C1500 5.7 automatic truck and she's giving me some weird trouble. So I just finished putting head gaskets on this engine like a month ago?
After adjusting the valves she ran perfectly, smooth as butter, excellent gas mileage, tons of power.
SO now, it's got a random misfire, very random. One stoplight I'll be fine, next stoplight it sounds like it's about to die.
I do believe that she could use a new dizzy, so that's happening this weekend.
But I unplugged the O2 sensor last night, just for giggles, and the truck didn't give me a check engine light, the light works, if I unplug a MAP sensor it will light up.
However, the truck warms up and I can hear the torque converter locking up, if you bump the brake pedal it will unlock and lock up when you let go of the pedal.
Any ideas as to why it wouldn't be reading the O2 sensor?

[Kudzupatch]

Do you notice that it is worse at small throttle openings?
If you step up a little when it does it, it seems to get better? If so I have the same/similar issue.

[c10sport]

Shame you're a few hours away from Austin, I'd hook it up to my laptop and see what is going on.

[Rod_Lei]

Nope, it runs and pulls, but you can feel and hear the random miss as you rev it up. And if you step on the pedal to accelerate 9 times out of 10 you'll hear it backfire into the air cleaner, into the muffler, or just bog down and then jump right back up to where it needs to be.
And I dunno man, if it turns out to be from a worn out dizzy I'd still like to find out what exactly this computer is thinking.

[Rod_Lei]

So I put a dizzy in it and the engine is a lot more responsive, the old one had play and the pickup coil was literally in pieces. But unfortunately it's drinking at least a quart between fillups and smokes. I'm thinking I've got problems with the rings.
I've got two choices, sell this thing, I want a 5-speed pretty bad,
Or rebuild the engine I have in storage from the ground up.

[speedygonzales]

Leak down test