LS1 rocker arms

[AaronGTR]

Thanks for the input guys but I think I am just going to go with the jesels for the lower profile and the strength with the shaft system. seems like using the others is going to be a pain setting up and getting the geometry right. Too much trial and error and I don't have the rockers to do it with. This project has been a major pain. I have been waiting on my crankshaft since november.

I would sooo get a reground cam before spending $850 on custom rockers. You are only increasing the ratio so you are only going to increase your max lift and nothing else. There are so many other improvements to be made with a cam. And if you don't think a re-grind will work, there may be another option. Cammotion is making custom cams for gen3 3400's for about $400. Brand new billet blank and any grind specs you want. They will work in all '95 and up 3400's, with the only issue being needing the correct cam sensor and/or small modification to the harness in order to work with the cam trigger which an '03+ style. I don't know about the cam trigger in 3100's, but the physical cam itself should be the same size as the 3400, so it should work in either engine shouldn't it? Might wanna check it out.

[eliteweapons]

I had the cam reground but need 518 lift to stay in the heads maximum flow range longer due to the low duration, got the duration up to 215. and I need the cam sensor for the 3100. I called cammotion a few weeks ago and they had no cam options for my engine.

[smilinguy99]

I can't tell if you guys are saying the cranes will work on the gen III or not because the threads seem to be bouncing all directions.

Yes, if you look around this site you will see others have used the Cranes on the GenIII with the GenII pushrod guides.

What seems to be in doubt is if the SBC rocker (or at least the one from HS) will work.

One thing you may want to pay attention to with whatever rockers you choose is the clearance between the tail area of the rocker and the bottom of the manifold. You will have to grind the manifold in a few spots above some intake rockers.

One other thing. I spoke with Jesel some years ago about the GenIII and during the conversation it became apparent they were unaware the GenIII even existed. They thought I was talking about the GenI (which they make parts for) until we straightened it all out. All that may have changed, but if there's any doubt in your mind, make sure they know which engine you are talking about.

If Jesel does make a shaft setup for your GenIII, make sure you post photos of those little gems on this site!

sg99

[eliteweapons]

Does anyone know the part number of the crane rockers used? I need a 1.8 or 1.9 ratio. Jesel told me to send the head and they will make it. I just wanted a little more info on the crane stuff to save some money as long as they work right. This thing is gonna be spinning to 7500 and i don't want her to come apart.

[smilinguy99]

I need a 1.8 or 1.9 ratio. Jesel told me to send the head and they will make it.

Oh. Well, the Cranes come in a maximum ratio of about 1.6:1.

In any case, the part numbers are:

25759-12 for the 1.6:1
25750-12 for the 1.5:1

The "-12" is for the set. If you just want to order one only, then change it to "-1"

Here's the web page with a description of the parts:

http://www.cranecams.com/index.php?show=browseParts&lvl=4&prt=108

Keep in mind these were made for the iron head motor and they just happen to work OK on the aluminum motor.

I think there is an article on this site somewhere about fitting the Cranes to the aluminum motor.

sg99

[AaronGTR]

I had the cam reground but need 518 lift to stay in the heads maximum flow range longer due to the low duration, got the duration up to 215. and I need the cam sensor for the 3100. I called cammotion a few weeks ago and they had no cam options for my engine.

Probably because they have no knowledge of the differences between a 3100 and a 3400. Other people had to do all the leg work for them just to find the differences between the 3 different triggers used on different years of the 3400 cam. They wouldn't know if a 3400 cam would work on a 3100 unless someone told them because they haven't researched it. Can anyone else chime in here and tell us if a 3400 cam will fit in a 3100? If the cam is the same size and the trigger is the same then you should be able to use it.

[bszopi]

The cams are the exact same. All you have to do is look up the part numbers from GM.