Greg check out this Monte site:
It shows you in stages, "how to build up" on the L69 305. It's all emissions legal, they
show the Trick Flow Speciaties Twisted Wedge
head,(fully smog legal), and add's roughly
50+ hp out of the box to your L69. It's not specific to the 305 but the narrow heart shaped combustion chambers and modified valve angles will clear the walls of the smaller
305 cylinders. As mentioned by jholp the L69 has 58cc combustion chambers to the 64cc of the TFS head. Check it out as I would be only quoting the build up word for word.
As a side note Greg, keep in mind that as time marches on, say 5 to 10 years from now,
these last rear wheel drive full frame
derivitives of the A body, 83 to 88 Monte SS's will become (in my opinion) classics. They might even be the Chevelles of the 80's
and clean, original cars will be sought after
more than modified ones.(Where has this played it's self out before?)Keep original parts for future "use".