engine prob

[Ackattack]

Ok, I need a little help here

Sometimes when I'm cruising along at say 1/4 throttle, and then gun it to say 3/4 to full throttle, my truck will do something weird. It sounds like to me maybe it backfires through the carb, but i'm not sure. It kind make this weird noise like it didn't fire and will loose power, then when I let off it will continue to drive fine. It mainly does this when it's not quite up to full operating temp.

Does anyone know what it could be? I'm thinking either distributor/timing or carb. It has done it with both the 600 edelbrock and 600 holley I've had on it though.

It's kinda hard to describe exactly what it is in words..but hopefully someone can help.