I dont normally do lawns but I was hired to do several stone walls and the home owner made me a deal I cant refuse. So with this in mind my plans are to rototill the existing lawn as its patchy grass and dead areas. It was originaly sod and for some reason sections died. I will do soil tests etc... My question is after I rototill the yard should I rake out the Chunks of grass or can I leave them in the soil. I intend to topdress with about 1-2" of soil. Thanks!