Hello all, I am gathering parts to build a new short block to go into my 79 Z28. I am looking to build a one piece rear seal 355 with six inch rods. I intend to buy a fully balanced Eagle rotating assembly, but I need to choose between a 153 tooth flywheel or a 168 tooth flywheel. The engine that is in the car now is a '73 block casting number and I do not know what sized flywheel it has. Are there any performance advantages between one flywheel or the other? And are there any fitment issues besides the starter? Any help would be appreciated. Thank you.