i have an 87 iroc with a L-98 350 and i have almost all of the bolt on's. The stock rockers are 1.5 right? So if i put on 1.6 would i get a gain in HP/track times.

 

u would notice a difference just b/c of them being roller rockers...wherever u can reduce friction=more HP.

 

They will reduce friction and increase your lift. Here is an easy formula to follow:

.450 say your cam has .450 lift
.450/1.5 divide the amount of lift by your current ratio you are running (1.5)

.450/1.5 = .3 lift at the lobe
.3 * 1.6 multiply your amount of cam lift by your new ratio (1.6)
.3*1.6 = .480

So you would jump from .450 lift to .480 lift by swapping to a 1.6 rocker.

 

i have an 83 305 lg4 carburated engine would the low friction roller rockers be a good upgrade? about how much power can they release? what brands are the best? and one last question.. is there any problem with piston clearance, the valves wont hit the piston with the increased lift will they?

 

roller rockers are a good upgrade on any engine, particularly stock. you should have NO problem with piston slap or anything like that with the added lift.

whether the $300 price tag of Crane Gold RR (have ones designed to fit under center bolt valve covers) is cost effective to you or not...is totally up to you.

if you wanted to just boost the lift there are stamped rockers that summit sells that are 1.6 ratio but NOT roller rocker, and i think they also sell 1.6 rockers with just a roller tip (not full roller). these alternatives are cheaper but will not get you as much hp.

i've read of guys dynoing increases of 10 all the way up to 20 hp with 1.6 full roller rockers.