With the extra power of your new cams, You might find the 4.56 trouble. The problem is actually in the TX - the first gear is very low, with a large gap to 2nd. This started with the little sub-80HP 1300 engines in the 50's, but with more power there is no trouble getting moving from a stop. Instead you have to shift to 2nd about the time you've crossed the intersection, especially if you made a vigorous departure.Hi Bill:
It still has the 4.56 axle! The new engine is revving well and I may not need to install the 4.1. And I have bought a 12.2 mm camshaft from Richard Jemison, so it may need that 4.56 ratio.