I new to this forum ,I currently drive a 2000,3/4,4x4,ccab,vortec5.7.And I am at the point of going into the motor at least under the valve covers to add some roller rockers.After reading that a set of 1.6 could decrease power with the stock cam would it be beneficial to add a set of 1.5's to this motor or just leave it alone. So at this point I am between a rock and a hard spot.Any imformation will be appriciated.
Thanks Paul

 

im not sure what the ratio is on the factory rockers are but you are going in the wrong direction. if it is 1.6 then you want to go to a 1.7 to gain lift.my preference would be for you to get a tune or if you are wanting to go in the motor then a cam would be more beneficial. but a tune will be needed then to get the most out of it. what are your current mods. this will help us help you.

 

stock rockers are 1.7 maybe 1.75
and 02 Denali is right you will waqnt to go up.
I put a set of 1.85 on mine and it changed theduration of the cam.
not physically, but changed the exhaust duration
gave it more lope on a stock cam

 

Stock is 1.7.

 

Stock is 1.5 on the old 5.7. Changing to 1.6 roller rockers should give a good power increase over the stock stamped rockers.

More lift and duration
less fiction

You need self aligning rockers for 1987up.

 

Hey thanks for that help on those rockers.some of the mods consist of the following ;80mm throttle body,hypertech programmer,8.5 wires,true dual exhaust
,gibson shorty,granatelly massiar flow,air aid filter,electric fans(pemracool).The motor is currently stock internaly.I now about the self aligning rollers,but I have read a few times that the push rod ports may need to be inlarge a little bit to keep the push rods from hitting the heads.
Is this the wright sight for 96-2000 year model vortecs.i did notice that most of the questions on this sight are refering to the newer engines 5.3-4.8's.
THANKS AGAIN BLACK02Z71

 

Get rid of the hypertech. my brother has a 96 Yukon and stepped up to a Wester's. The difference was unreal, truck really felt like it was benefitting with the mods he had done (intake, k&n, TBspacer, magnaflow cat-back, full MSD ignition, electric fans). If your hypertech is the same as his, then the instructions say that the max it can handle is an aftermarket exhaust and intake. after that it will hurt performance.

Wester's http://westers_garage.eidnet.org/ , Tbryne (a supporting member here) also sells them too

Nelson performance www.nelsonperformance.com (not sure if he does the 5.7 tunes)

 

Thanks for that imfo on those pcm's and programmers.I will give them a call before christmas.But i still need to no about any head work needing to be done for a set of self aligning 3/8"stud 1.6 roller rockers.Has any one out there put a set on the 5.7 and had to do any head work.
Thanks Paul

 

My buddy's truck felt alot better after installing the 1.6s on his R motor, this includes towing. However, you have to drill the pushrod holes in the head. The pushrods will rub against the head. I believe you have to use a 5/8 drill bit but, don't qoute me.

 

On the vortec heads you don't have to enlarge the push rod holes, gust use self aligning roller rockers. I put 1.6 rockers on my 96 5.7 vortec they worked great!