Robert my distributor does not have vacuum advance. The 68's did not come with it. It is easy to put back the butterflies if things do not run right. I sure would be tempted to leave a vacuum advance in place if you have one
Bill I have thought about putting in plates like you mention to close off the crossover. Do you know if it improves performance even more to do that ?
Yes I did notice the shafts can move with the butterfies removed but have had no problems with leaks around them and the linkage seems to hold them adequately so far for me. It is one of the first places I check if I get an engine miss or change with the idle.
David Barnes
68 E-Type FHC