I've got an 86 2004r auto. trans. and a lockup conv. from an olds cutlass. Any reason the conv.wouldn't fit a sbc? It will pull up within 1/4 in and seems to stop,I don't want to force it for fear of cracking the transmission. I tried to make sure the conv. was seated but still had no luck,never had this problem before.

 

It's probably not seated fully in the pump. Measure from the flexplate pads to the rear of the block and from the converter
to the face of the bellhousing. Converter measurement should
be about 1/4" more. The saying "If it don't fit, force it!" does
not apply in this case.