Im guessing as to what youre after , based on your post. Trans wise, a rebuild with the red (rv and plow , heavy duty style) clutches and bands , along with a trans go shift kit make the 'flite happy. Assuming local cruising , a 3.23 sure grip does all you need, maybe 3.55. Engine wise, for the money and expected power return , Id go cheap cast crank emissions era 440. Cast or forged pistons (hyperuetectics are a no-no in my book), 440 source aluminum heads with a going over by a good engine builder, and a lopey cam that falls short of needing a converter any more than 2,500 stall speed.Keeps your small inch matching number on the stand (even though im apparently one of the few 383 fans),and takes advantage of cheap easy cubic inch.