Question on swapping transmissions

I'm putting a th350 on a 1967 283 that had a powerglide. I did a search and read elsewhere from several people that it would bolt right in. I had a 454 bolted to the same tranny, but now I'm selling the car so in goes the 283. I have it bolted in the car and to the tranny, all is fine there. So I go to bolt the torque converter to the flex plate, there's about 1/2+ of space between the two and I can't make the converter pull up flush with the flex plate. Is there a difference in the flex plates?

Thanks for the help in advance.

Junkyard

 

should not be any difference.

you didn't put the flex plate on backwards, did you?

 

No, I never took it off the engine when I pulled off the powerglide.

Junkyard

 

Occasionally I've had to sand the hub on a rebuilt torque converter so it slides easily into the crankshaft. If the 283 sat around a while the crankshaft bore where the converter hub seats could be rusty.

 

Thanks, I will check that out.

Junkyard