I have a '89 Iroc with a 305. I was wondering what would be a good rocker upgrade over the stock? My cam is most likely going to stay stock for awhile due to money. But if anyone could give me links or part numbers/advice it would be greatly appreciated.

 

You may be S.O.L. on using 1.6 rockers without enlarging the pushrod guide slots through the heads. The 1.6's move the pushrod closer to the rocker pedestal, and sometimes the slot/hole has no clearance in that direction to run anything more than 1.5's
Can't be sure without checking for yourself, but I considered this a long time ago when I replaced the valve seals and had a set of 1.6 rockers in the garage. The 1.6's made the pushrods interfere and I didn't want to risk elongating the slots without removing the heads.
If you're lucky, somebody who knows for sure about your specific engine model/year heads can chime in and let you know if my caution is warranted. Or.......you could just have a look for yourself

 

in my experience i have never had good luck with 1.6 rocker vs 1.5. Is there any particuler reason you are looking to upgrade rockers? are you looking for more HP without diving in too deep?

 

http://www.summitracing.com/parts/su...6-16/overview/

http://www.summitracing.com/parts/cca-7808-16/overview/

http://www.summitracing.com/parts/sum-g3314/overview/

 

My 305 build. Posi valve seals, Comp beehive springs, Comp Roller Magnum rockers 1.5 and Comp CM rods.

If you're swapping out the rockers, don't forget to add seals. Cheap insurance.