Not sure if that puts a damper on this 391 swap now or not . If it does I always have the motor out of that 311 I just looked at the bearings on the crank are shot but top end is still very healthy. A few minor scuff marks but will still blow good compression. Balls in your court now . I can send you everything I have to do the 391 swap or I can send you the stock 311 used piston and cylinder