Need some help !!!!!!!!!!!!!!!!!!!!!!!!!

If you do not want to trim off the head gasket tabs, here is another way to make this measurement valid. Get some flat stock aluminum or steel or lexan sheet (anything hard an of consistent thickness) 1/16" thick and cut some pieces to put on top of the china walls front and rear. This will 'set' the intake on even shims above the china wall, and make the intake flat to the china wall ends. Then slip it to one side and see if there is that same large taper in the gap on the other side.

But again, this method assumes that the chain wall heights are level front to rear, and relative to the head surfaces on the block. If the block has been surfaced crooked , or if the china wall top surfaces were never even to start with, then this method is going to show the intake crooked to the heads regardless. Ultimately we don't care if the china wall heights are even, as those gaps are being filled by sealant or end gaskets. What we do care about is that the heads are parallel front to rear. Making checks with the gaskets in place and seeing if everything is even front to rear and side to side is what counts.