Yeah you can use that 84 front cover with the 84 block, as long as you have the 84 oil pan also. That hotair stuff is all 14 bolt on the pan, so your intercooled motor pan and cover are a no go. I don't think the steel caps are necessary for a mid 11 car. There are too many high mile stock motor cars with a cam, springs, turbo, ic, converter, and tire cars going a lot faster than that for me to think that would be necessary. As mentioned before my car on the lowest boost possible has the potential to hit 11s (by looking at my mph, anyway) and I am running 14 bolt block with stock crank, rods, mains, and even hyper pistons. I know if it goes lean, it'll shatter that piston, but I am going to be methodical about it. I don't think I can will make enough power (67 turbo and gn1 heads) to shake the mains enough to need steel caps. We will see. The forged pistons would be a much better buy than the steel caps. Do the cotton pistons have any part numbers on them?