I'll say something that hasnt been said...your tires are part of the problem with your car being a stickshift...
the design of the cords inside of a radial tire make them a softer design and less resistant to the "hit" that a stick shift gives on launch at a drag strip...a bias ply on the other hand has the cords wrapped differently, making them stiffer but also creating a different footprint that helps to better control the launch of a stickshift car...the theory has been tested, tried and true- guys who run radials in stick cars usually pick up atleast a tenth or more (some as much as 3 tenths) when switching over to a bias ply tire, while also having improved launch characteristics (car launches straighter, etc.)..
not too mention that radials on the stick car dont provide the give you need to help save your drivetrain, and in my opinion anything you can do to help "soften" the load on the drivetrain in a stick car is something you should do...in my opinion you should be looking at running a tire like the ET street, MandH DOT racemasters, MT sportsman pros (hook like crap but are nice and stiff)...and dont let people fool you that bias ply are dangerous or inferior- they were used forever without problems, and from the sounds of it you dont seem to be corner carving this thing anyways
thats my two cents, take it or leave it....some will agree, others will disagree, but the proof is in the facts...if you dont believe me talk to any stickshift drag racer, and i mean a real racer, and they will tell you the same thing
good luck!