I have an '88 OMC Cobra with a SBC 5.7. The engine is freshly rebuilt last year and the u-joints, gimbal bearing, and u-joint bellows have just been replaced 2 weeks ago. I can hear a noise that is very hard to describe ONLY at WOT. If I back it off just slightly (say from 4600 rmp to 4500-4550) it goes away. The noise is not repetitive (fairly sporatic). It is not a knock, almost a high speed jiggling noise (for lack of better description). <br /><br />The only thing I can think of that reminds me of this noise is when I used to pull a tube behind an outboard and the cable hookup to the boat had a wheel on it to allow it to go from side to side. As you would turn the thing would move on the cable 2 ft really fast and make a similar type sound (that may have only confused everyone :-( <br /><br />Anyway, can anyone think of what it might be as it is only at 100% WOT??? This may not be related, but at WOT everyonce and awhile it will miss, but this doesn't necessary coincide with the noise and is most likely just worn points which I will be replacing in the next week or so. Timing is set correctly. It seems to come from the port side of the engine compartment but that is me listening to it by myself from the driver seat at 48 mph... <br /><br />It wouldn't be a good idea to rev the engine that high when not in gear, right....?<br /><br />Thanks!