8675309

iTrader: (3)

What kind of gains do you see from just doing roller rockers on a bolt on z28? I've been thinking about doing some 1.7 roller rockers on mine. How much horsepower would I get out of that?

RamAir95TA

iTrader: (2)

You can probably expect 10 or 15 rear wheel from going to 1.7s. Stock valvesprings will be past coil bind with 1.7s, so I would recommend upgrading to the Crane 10308 kit. The popular replacement LT4 springs will be marginally close to coil bind and I wouldn't chance it. However if you went with 1.6s, you can use the LT4 springs without a problem (seriously cheaper) and see similar gains. 1.7s might need to be clearanced for the springs too, but I have no first-hand experience with 1.7s.

SoxXpupPeT

iTrader: (34)

1.7's are good for stock cams but if you plan on upgrading cams the 1.7's mighe be abit much. i went with 1.6's and noticed a much smoother and torqueier lower end and a peppier upper. i also have CC 918's. idk what exactly # gains i saw but it was noticeable

8675309

iTrader: (3)

I'm not sure if i'm going to do a cam or not so I think that I'm going to go with 1.6's just to be safe. Can I run them on stock springs? Or will i have to get new ones? Could you show me some good 1.6's and some good springs to go along with them.

ss.slp.ls1

iTrader: (36)

Get Comp Cams ProMagnum 1.6 NSA roller rockers. You will have to use guideplates and hardened pushrods.
No, you cannot use stock springs, cheapest route would be to get some LT4 springs. If you plan to go with a cam, I would use some Comp 918's or some PAC 1218's springs.

Elliott's94Z

iTrader: (12)

10-12@ the rear

sdm1234

iTrader: (8)

You can use stock spring with 1.6 RRs. There have been many successful stories about that. Out of personal experience, I gained about an average of .2sec & 1.5mph with my 1.6RR/matching PCM tune. With the 1.7s, you'll need new springs, no doubt. As Elliott's94Z said, typical gains from 1.6RRs are 10-15rwhp. You'll need a tune though, so the PCM doesn't cut back on injector pulse.

8675309

iTrader: (3)

so if I run 1.6's I can use stock springs and push rods? And I plan on getting a mail order tune anyways so that's not a problem.

RamAir95TA

iTrader: (2)

I know there have been success and horror stories with using stock springs, but for the price and reassurance I HIGHLY recommend at the very least upgrading to the LT4s. Float and coil bind are two very bad things that can be eliminated for $40.

SHDY 5.7

Im also looking into doing this. So with lt-4 springs and 1.6rr's im good? I really don't wanna dig into doing rods though.

ss.slp.ls1

iTrader: (36)

Yes it will work fine. LT4 springs can be had for $50. But if you ever plan to do a cam, I recommend that you get 7/16" stud NSA full roller rockers (Comp 1.6 NSA ProMagnums for example). That will require ARP 7/16" rocker arm studs ($40), guideplats ($16), and hardened pushrods. Then when the time comes for a cam, you just have to upgrade your springs, and slide the cam in, that's it, the rest of the valve train can be reused and can take just about anything you throw at it.

BlackLT1Z

iTrader: (11)

Yes make sure you get self aligning rockers though. You will have to if you wont be replacing guideplates or pushrods.

SHDY 5.7

Ok. Thank you guys.

SHDY 5.7

Ok. Thank you guys. Will this clear a stock valve cover?

BlackLT1Z

iTrader: (11)

Yes with some modification. You will have to cut a small piece of the brace out. Do a search. Someone had pictures on here of exactly how to cut them.

ss.slp.ls1

iTrader: (36)

http://www.golenengineservice.com/html/lt1_facts.html

click on the link and scroll down to the bottom. Cut the supports as indicated and you should be able to fit just about any rockers.

8675309

iTrader: (3)

so if I got this set of rockers
http://store.summitracing.com/partde...6&autoview=sku
Could I just get some lt4 springs and then thats good? Where could I find the lt4 springs too? And sorry for being such a noob about this. And dont worry I'm not doing it myself I have a friend who is going to do it and I'd help him.

ss.slp.ls1

iTrader: (36)

Yes, you'll be fine. You can search for the springs in the classifieds section.