Clutch question

So, just got a new long block installed and also installed a new clutch at the same time. The 'reputable' mechanic that I used is starting to cause me to question his reputation. Maybe this is not an issue, but I feel like it is. When I am taking off in first or in reverse, the clutch disengages fine as the car starts to go, but at the end of the clutch being disengaged, the car shakes horribly. Almost like a stalling out feeling, but much more aggressive. The clutch has about 350 miles on it now. It does it the worst when my rpms are between 1200-1600. If I rev up to 2k or so, it goes away. Is this a break in feeling or did the 'reputable' mechanic fuck up the installation. I have the ACT 6 puck clutch kit. What are y'alls thoughts? Thanks.

 

Not sure on the ACT, but with my Southbend, there was a 600 or so mile break-in period. no hard launches, and just driving lightly.

 

I'm good on the break in... I'm still doing minor pulls while the engine breaks in as well... But I dont think it's normal for it to shake the ever so living hell out of my car when I'm starting to go.

 

Not sure my man, might be just the ACT.

 

This is my second ACT... I don't recall the first one doing it. Is there a possibility they installed they disc uncentered? Or possibly didn't torque everything correctly? It somewhat feels like part of the clutch is more engaged at certain points. Like a wobbly feeling. I suppose I'll need to take it back to this damn shop to have them double check everything.
[doublepost=1465581519][/doublepost]Would a loose motor mount cause this too?

 

Very well could be. Take it back.

 

A few hard slips is all that is needed to break in an ACT 6 puck, there should be no further breaking in afterwards, looks like something is fucked up.

 

I'll get it checked out and post my findings. Maybe it just has a harsh bite that I'm not used to. Maybe it's not slipping as much uing disengagment like I am used to... I am not sure.