Right on, 3.4's rock! A bone-stock 3.4 would still be better than a modified 2.8.
Chip is wasted money IMHO and if used would be on top of all other engine mods. You can make some of the gains that a chip would give you by simply advancing your timing 3 or 4 more degrees from the stock 10 deg BTDC setting. Or cranking it up to about 15-16 degrees and using premium gas, which is likely what you'd have to use with a chip anyway.
For the bucks, a better exhaust and 1.6:1 roller rockers will give you a lot of extra performance. 2-1/4" is a good size for 2.8's and 3.4's too, if you have a 3.4, 2-1/2" will breathe a bit better (overkill on a 2.8 however).
Upgrade the intake side while you're at it; simply invert the air cleaner lid; use a K&N filter; add an extra snorkel to the existing housing(that's what I did); install a better-breathing air cleaner assembly; or DIY cold-air induction.
The Holley (or modified GM 4.3 TBI) and bored-out intake manifold would be a good addition atop all the above mods. If you have stock exhaust and intake you won't see much gains with the Holley and it will be "overcarbureted".
If you haven't seen this at the Outdoor Wire, it's a good primer for the budding 60 deg performance enthusiast:
http://www.4x4wire.com/tech/60degreeV6/?
HTH and Power to the V6 Right On..............ed