Ed, the 1.6:1 rockers are a definite improvement, although I think the most pronounced effect is on the mid-to-upper end rather than low-end torque. All I know is that my 3.4 with Donormaro motor, stock cam, 1.6's, Holley, etc, has so much torque and immediate response in 1st gear 4-LO that it's almost unuseable. It just leaps forward like you can't believe. But if you take your foot off the gas it'll crawl like mad in 1st.

The cam found in the Goodwrench HT 3.4 crate motor is known for its superior torque characteristics, and even though you aren't planning it, having the heads off is a good time to do a cam swap if ever.

Check the cam lobes and lifter faces carefully for wear. The lifters should autorotate as you're turning the crank; if they don't, the lifters and likely the cam will need to be replaced anyway.

Here's a good discussion about cams and torque issues at the GMForums site:

http://discussions.gmforums.com/showthread.php?s=34be06697657ca31886e20f5426952cd&threadid=33902

BTW for G.P. be sure to replace both head gaskets, if one decided to blow it's not unlikely that the other one may be next.

Not sure about the Torque-to-Yield bolts, I would think that if you stuck to name-brand aftermarket ones there'd be no problem.