Originally Posted by jay1214
I was wondering if there was a difference in the 4.3 I have a 90 Chevy k1500 5 speed bad motor so I have another but it came out of a 89 van that is automatic flywheel off my 90 will not fit the diameter on the 90 is smaller than the auto what do I need to do
The stick shift flywheel will fit the crankshaft of the automatic-equipped engine, use the same parts from the stick shift engine on the automatic engine (or replacements if your parts are worn). Don't forget to install a pilot bearing in the crank of the AT engine if that's the way you're going to go. You need to use the starter from the stick shift engine as well.
More info on the Chevy V6 here