[WSSix]

Ah, well that changes things. I wouldn't mess with the 5.3 heads at all except to make sure they will work and survive until you can afford better heads. Don't even consider the LS1 heads. Skip straight to LS6/243/799 heads at a minimum. That or go aftermarket.

I would also consider a smaller cam. LS engines can take big cams thanks to the PCM but they aren't needed to make good power. I also prefer and recommend to have a broader power band for a street driven car. That cam will work and perform well but I feel you'd be giving up too much low end. Stick to a cam in the mid 220s on a 114 lsa and I think the car will be a lot more fun to drive around. It'll still have a lope to it but it'll be less radical.