Ok. It would be good to get more info but a new short block is always welcome. Lol. The sloppy shifter can be fixed by getting an aftermarket shifter. The two popular brands are Barton and MGW. MGW is what most people recommend but both will work well and give you crisper and shorter shifts (make sure you also get the bracket if you pick Barton). For the high rpm shifts, make sure you've got the simple stuff down: the clutch is fully disengaged until you are in gear and you aren't accidentally not shifting into the right gear or something. The only reason I say this is because a few people have "solved" their high rpm shift issues with an aftermarket shifter. I'm not calling you a newb but sometimes it's the simple mechanics that get us. If you are doing everything correctly, you should mention it to the mechanic and probably bring it in for them to take a look. If the previous owner beat up the engine, he probably also put a beating on the transmission...at high rpm.
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