How do i stop tail happy under acceleration

[Pownabown]

Right guys im running my cougar sv and i really think
its great for riding the bumps and jumping,
But i seem to get the back end kick out alot
under acceleration from the corner.

The grip into and mid corner is great but under acceleration
out of corners it kicks right out.

How do i stop this? do i get a new rear brace of 4degrees
or stand the shocks up on the tower maybe.

Can never remember if its standing shocks up helps or laying them down on exit traction.

Any helps much appreciated.

Or maybe try the longer chassis would this help?
Im running on astro using staggers on front and yellow spikes on rear