zulu723

Need advice...alot of recommendations for upgrading to the 1.6's and what will be the actual gains ?

Next, what additional work will be needed for this to wotk on stock heads, valve covers, etc ?

Will it be worth it to upgrade to the full length 7/16" rods ?

Thanx !!!!!

foxbat

do some searches on this. some have reported 7 rwhp, while others have reported around 20 rwhp. this month's gmhtp has an average of 10 rwhp. be sure to get new springs when you're doing this.

zulu723

So you are saying all I need in addition is new valve springs ?

Bud M

No, what he's saying is that a search will turn up all of the answers you need.

Compstall

I gained 7 rwhp with them on the dyno. 2 lbs of torque also.

wrd1972

Zulu723,
I will help you out.
I did a full RR install and I will speculate about 10RWHP and a noticeable improvement in the seat of the pants. The engine now pulls much harder in the higher RPM ranges without choking like with the stock components. This is a very good upgrade and I recommend it IMHO.

If you decide to go 1.5 ratio RR’s then you do not need to replace the stock springs. If you go 1.6 ratio you really should replace the springs cause if you don’t you may completely compress the stock springs which tends to make things explode. The other advantage of replacing the soft stock springs with stronger springs is you will reduce the amount of valve float at very high RPM, this means that the lifter remains in complete contact with the cam with out floating due to a weak spring. If you go non self aligning RR’s you will need GM guide plates and hardened push rods, do not use any other guide plate but the GM. If you go aligning RR’s you will not need guide plates or hardened push rods. The advantage of using NSA RR’s and guide plates and hardened push rods is the components tend to be more stable at higher RPM and some say that they run quieter too. There has been much discussion about which LT1’s come from the factory with hardened push rods, some say 93-95 have them. Im here to tell you that my 1995 LT1 DID NOT have them so I replaced them with new hardened push rods. I also installed the 7/16" studs, this is not essential but it is added insurance for a few dollars more. It has also been stated many times that the Comp cams beehive springs are among the best springs for most any application and accomidate most ratios of RR's. I decide on the LT4's because they are insanely cheap, you can get the springs, retainers, locks for less that $65.00 shipped from many places such as sdpc2000.com

I installed the following on my engine:
Comp cams 1.6 ratio NSA roller rockers
LT4 valve springs
LT4 spring retainers
LT4 locks
GM LT1 guide plates
7/16" studs (optional)

As far as special tools go you will need a valve spring compressor. It took me about 5 hours to install all the above components on my engine. The install is not difficult at all, just very time consuming. The hardest part is replacing the springs on the rear of the engine due to limited access. If you only plan on installing just the RR’s you can do that in about an hour and a half. The adjustment of the RR's is very easy to do if you have poly-locks which normally come with most RR's. Lastly the RR's make a very slight ticking sounds but definitely are not loud, however you can clearly tell they are in there.

Regarding valve covers, the stock covers will work. You will need to flatten out the structural ribs with piers for them to clear the RR's. This is easy to do and only takes a few minutes to do.

I believe it’s a waste of money to just install 1.5 ratio RR’s using stock springs and such, you will not see much of a gain. By going with the 1.6 ratio RR’s and stronger springs you will feel the gains, it’s kind of like adding a bit more cam to the car. Many have installed 1.7 ratio RR’s on their engines but others have commented that it is risky. Taller ratio RR’s make it more vital that you install the correct springs or you will have problems.

If you install RR’s, springs and a good set of headers I will bet you will shave a full .5 of the 1320. These are among the best things you can do to ensure the stock heads flow the best they can plus the car will be much more fun to drive.

I think that should just about cover it.

Critter

nice!!! ^^^

wrd1972

bump

BMoney

that is very nice to read, im actually doing the same thing right now. not to take over this thread, but how did you install the springs and set them up to the correct hight? or did you just put them on. one more thing if you put 1.6 rockers on what did you do with pushrods? Length? and style, I seen that they have pushrods for oem rollers, they are about .600 shorter than standard ones. and about the guide plates? you said only GM ones, is there a reason for that? I have a set of comp cams guide plates I was gonna use. thanks
Brian