I just got the new jegs catalog today and saw some rocker arms for the 2.8. They are made by comp cams and they claim to give you 15- 30 hp. I was woundering if anyone has done aftermarket rocker arms and what difference did you feel?

 

Are they full roller rockers or roller tips? Whats the ratio? 15-30 hp is highly unbelievable. I'd say 5-10, 10 being absolute tops...

 

small block rockers fit our motors too. just watch the stud size, i think we got a metric size (10mm i think) where small blocks are normally 7/16" i believe. i am running 1.6 roller tips for a small block on my 3.1 i just reused the stock pivot *****. small block rockers are probably cheaper and definately more common.

 

the ratio is 1.52 on the rocker arm

 

the part number on jegs website for the magnum rocker arms is 249-1413-12.

 

15-30 hp out of rockers only 1.52 ratio on a V6? Hehehe....suuure.
Those aren't even FULL roller rockers, they're only roller tipped....


You'd be better off with some 1.6's....add some more effective lift to the cam. And get full roller rockers if ya can for a decent price....

 

Do not go bigger than 1.52 unless you replace valve springs.. My buddy did it on his tired 2.8 and it became a real dog... He lost power low end big time... 1.6 roller rocker I think 105# valve springs are the key..

 

Comp 1413 rockers are 1.52 ratio. Comp 1414 rockers are 1.6 ratio. They are the only aftermarket rockers specific for the 2.8, 3.1, 3.4 10mm rocker arm stud. Use GM valve spring 12363215. Valve springs can be changed without removing the heads when going to Comp Magnum roller tip rockers.

 

I coulda swore that small blocks used a 3/8" stud... not 7/16"... no?

 

Small blocks and 4.3 V6's use a 3/8 rocker arm stud. 60 degree V6's 2.8, 3.1,& 3.4 use a 10mm rocker arm stud.

 

my fault, sbc's are 3/8 not 7/16......i got mixed up.