sluggish in 4 on the freeway
 

got a 350 mated to a sm420 4 speed w/ granny gear in my 4x4. down shifted into 2nd on accident and got a temporary 7.5k on the tach :burnout: sounded baaaad. then on the way home i'm driving fine on the street through 3rd gear, then the freeway and as soon as i hit ~60mph my motor became sluggish, down to third...still sluggish...back to the street and fine even in high rpm in lower gears. also fine in rpm range in neutral. chime in?

Re: sluggish in 4 on the freeway
 

You may have lost your vacuum or mechanical advance, or stretched your timing chain. I think you would have known if you floated a valve or bent a push rod or two.

Re: sluggish in 4 on the freeway
 

I used to blow out mechanical fuel pumps like crazy when I over reved. I used the cheap-o ones because they had a lifetime warranty. After the fifth one I switched to an electric one and the problem went away. Mine was the same way, lost power under heavy load, but would pull through the lower gears fine.