I'm wondering how exactly does a higher ratio rocker arm affect the valvetrain? I'm assuming the pushrod is moved closer to the fulcrum of the rocker causing a higher valve lift. Does it also affect duration, reliability? How about valve noise due to a more aggressive opening and closing? I heard they give the engine a "lopey" idle. One company claims significant power with a 1.6 intake, 1.5 exhaust. What would they do for my mostly stock '91 L98 (straightend exhaust,T.C.3.07). Thats a pretty good chunk of change for something that may or may not do me some good. I won't be changing camshaft anytime soon. Any one have any experience on this?

More lift, faster ramp.

Shouldn't change the idle

I hear 1.5 to 1.6 RRs are good for 10-15HP

Don't forget the springs may have to be changed too.

Probably more like 5-7HP on a stock cam vette. And you can run the factory springs, though your springs may be tired depending upon mileage.
Aaron

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Thanks, I always suspected that 10-15 was over rated.

No coil bind going to 1.6? Just wondering.

i wouldn't do a split rocker ratio cause your cam already has a split. that is geared more for the old school cams that were like 280/280 .480/.480 and every new cam has a longer exhaust duration and usually a higher exhaustlift.

Thanks for the input. I believe your right, P. According to my notes the cam specs are: @.050" lift in./ex. w/1.5 rockers .413"-.428", 202-207deg. lobe sep114.5.

The TPI guys that use the 1.6 typically like them on the intake only. For some reason putting them on the exhaust also tends to give it a slightly rougher idle than stock.

Honestly it isnt worth the money for what tiny gains you may get. Save up and do a H/C. The money spent for maybe 2-3deg dur. gain and what, maybe +.030 lift..Nah.