You can go w/ the 1.72 if you don't plan on a cam change.
At least the 1.7's though.
Get rid of the thermactor bump, clean the exhaust side and do some bowl work.
Are you doing the work yourself???port work and R&R....If your paying for it then get a set of used iron gt-40's.(i've seen 'em for $300...but not p's)
You can pick up some decent power from the stock heads, but if your paying someone to do it, it's not worth it.
If it's just a few hours and dirty fingernails for a couple days then hell yeah.
I would do mine if i were confident enough.
Oh yeah...and a good valve job..maybe polish them while your at it.
But instead.....i gotta wait.
------------------
4.10's,long tubes & 75 shot...Goes 12.50's
Check it out at
http://www.burnouts.webprovider.com