I can't help with the distributor part of your problem since I kept the Opti. But I had the same issue with the headers and the steering shaft. First, did your cut the corner off your motor mounts like that manual says? I also noticed the two headers are identical and will fit on either side. One of them fit better on the drivers side. If you look closely you'll see Sanderson's quality control isn't all that good for position of the pipes in the flanges, mine were off by 1/8". I still ended up having to grind off the Sanderson emblem on the driver's side to get clearance, but it is tight. I did slot the Datsun mounts but by the time I got the engine positioned I was in the middle of the slot.