Parts I purchased today for my 383 budget build any suggestions

Please stop buying parts until you have known measurements of what you already have. LY rods are 6.760 CTC length. Stock 383/400 B motor rods are 6.358(ish) CTC.

I'm going to bet the block will require between 010 and 020 to clean up square. The last two 400 blocks I did cleaned up at 9.965 deck height. This is to your advantage. If the rods are stock 6.358 length, the KB400 is a good choice as long as the rings are set using the proper gap, which is larger for the hyper explosive pistons. S/F.....Ken M