EB thanks again for the advice. I've been running 'round the last couple of days trying to find a machine shop I trust to machine my parts. I read what you said about port and polishing the head and was still wondering: Is back pressure a key ingredient in 'Yota performance? I've thought about going ahead and porting and polishing the exhaust side to let it breath a little easier with just a little work on the intake (just smooth up a few rough spots, not a full port on the intake.) I know what happens when intake porting get's out of control: high rpm engines are born and "bye-bye gas friendly daily driver." Would a good exhaust port cause any harm or do I need a certain amount of back pressure? I hate to keep aggravating but I've found that the answers from here are a lot better than the ones from the grinning, "built a hundred of them" teen-ager working down at the NAPA!