Ive never installed them before, and dont really have a clue. Im willing to learn but first i need to know what to buy. Of cause the 1.7 rockers, springs (recommendations?). But do i need hardened pushrods? Guides plates? What else?

Thanks,
Robert

 

Most guys that install rockers on LT1s go with 1.6 ratio...is that what you meant? Or are you truly going with 1.7?

 

No, 1.7s have been the craze lately.

It depends if you are getting self aligning or non self aligning.

For self aligning you will need the rockers and new springs.

For nonSA you will need guideplates, rockers and springs. You also need hardened pushrods when you use guideplates. 93/94 and maybe 95 already have hardened pushrods, newer LT1s don't.

Some people also choose to upgrade to larger studs, you can order the rockers for 3/8 or 7/16 if you upgrade them. Stock studs are 7/16 where they go into the block, but then only 3/8 up top, so you can upgrade to a full 7/16 stud without machining the heads. I'm not saying thats neccessary, but now is the time to do it so you don't have to buy two sets of rocker. The polylocks you will need should come with the rockers.

Bret Bauer
Or
Combination Motorsports
could hook you up with springs. Or wherever your ordering the rockers from should be able to get you springs. I would definitly get springs rated for .550+ or .600' lift so that when you decide to add a cam 6 months from now you'll be good already A better spring then neccessary certainly isn't going to hurt anything.

-brent

 

I think that using 1.7 rr's on anything but a stock cam is pointless... the lift created with a decent sized cam on 1.7 rr's could get quite high. better to use a cam with a good amount of lift with 1.6 rr's, less fab work to do. Well that's my opinion at least, people have been using 1.6 rr's to achieve their desired lift successfully, I see no reason to change to 1.7's other than the "My rocker has one-tenth better ratio than yours" argument.

 

What do you mean by that?

I agree that the lift with a cam could get a little ridiculous. The 1.7s are further away from the geometry that the heads where originally designed for. Higher ratio rockers do have the benefit that only the valve is being lifted more though. Example, if you achive the same valve lift with a mild cam and 1.7s, and an aggressive cam with 1.5s, the lifters will not be moving as far with the mild cam 1.7 setup and your valvetrain will be slightly 'lighter'.

I'm certainly not running out and buying 1.7s to replace my 1.6s

 

With the 1.7's though, you can take an off the shelf cam (like me with the 224/230) that has a nice very street/power friendly duration, but which a lot of people seem to think is a little light in the lift dept. For instance, on the 224/230, the lifts are as follows:

1.5 1.6 1.7
Intake .503 .536 .570
Exhaust .510 .544 .578

The 1.5 rockers really don't get too much out of a ported head setup. The 1.6 rockers help out, but if you have a set of ported heads that continue to flow above the cam life, a set of 1.7's would give you the lift of those bigger cams without the decreased driveability of a high duration cam.

 

LOL! I think I might. A friend and I are thinking about going in on a set to replace our 1.6 Intake rockers with 1.7's (Both have CC306 cams). If we decide to do it, track and Dyno numbers will be posted.

 

Ditto on my setup, should be ordering them today.

 

awesome fastbird! let me know how it turns out. I am in Japan (Guam next month) for another couple months and will not be able to do this till after I get home.

 

Not to Hijack, but Guam huh?? I like that place!! Good times. What part of Japan are you in?

 

I am in Okinawa right now...but supposed to leave for guam next week

 

I am selling my 1.7's for 190 shipped. They got 40 miles on them. Too much lift for my springs/cam.

 

Question: Although going with higher ratio and lift doesn't change the built in duration of the cam profile, wouldn't the higher lift affect the duration some anyway?

 

Nope, duration is duration. It just opens up farther w/ a high lift.

 

I want self aligning. But only ones on flatlandracing.com that are self aligning say "Chevy - Self-Aligning 3/8 Vortec" and the others dont state that if there SA or nonSA, so im assuming they are nonSA?