1. Y

    New never used GN1 heads

    Hey guys, I'm pretty new to this forum (and forums in general) so please forgive me if in doing this wrong. Background first, basically, my 1987 grand national doesn't shift under WOT from 1st to 2nd. It will at about half throttle, but in WOT it just refuses to shift and revs out. Every other...
  2. W

    transmission vibration in low gear

    Hello, I've searched and found nothing on this issue.. I replaced the front pump boost valve (.471 to a .555) trying to get a better grab on my first to second shift, I also replace the 1-2 accumulator with a block off plate from ck, and I get a severe vibration on low gear, I even put the .471...