Transmission issues

[Kalums]

Ok here is a random one and hopefully someone has experienced this or understands... Ok finally dropped my "K" block 350 in my 1971 GMC and.... For some reason my flexplate and torque converter are about 3/4-1" apart... I can scoot the torque converter forward towards the engine but then it isn't connected to the pump... Also when I install my starter, the flexplate is ON the opening for the bendix. Not like I need shims, but like up against the opening, again not up against the teeth(top or bottom of the starter) but against the flat edge(side) of the flexplate teeth. The flexplate is far enough away from the torque converter it makes me VERY wary of putting shims in. Local trans shop said 1) I may have the wrong flexplate (even though it is a pioneer 168T with an external "batwing" weight, "for one piece seals") or 2) I may need the LS "crank spacer".
BTW it is a TH350 with an NP205

Have any of you guys had similar experiences? Thoughts? Ideas? I want to get this sucker up running again... But man this one is too much for my limited knowledge.