I put a 1980 C4 in my '86 ranger and it seems to shift to soon and was wondering if anyone knew when it's suppose to shift? (either speed or vaccum) I had the transmission in my 302 '83 and just adjusted it to what seemed right but i would like it shift at the ideal time and my '86 has more vaccum. I know how to adjust it i just want to know when the ideal time is. I also have a shift kit in it as well. thanks for any help.