LS1 springs

[v6h.o.]

The 3.1/2.8 valves are slightly different. The retainer lock groove in the valve stem is a little closer to the end of the valve on the 3X00 (maybe 0.080" or so). This will affect spring installed height. You would have to play around with mixing and matching valves, retainers, and locks to get everything right.

Marty

ah shit.. your completely right marty. i completely forgot about that aspect of it. my mistake..

[AaronGTR]

Question for everyone. I've got my heads finished and the LS1 springs installed. Got the guide plates on and test fitted my crane roller rockers. In the directions for the rockers, they say that when using them on aluminum heads that originally had the self aligning/self adjusting rockers and using the guide plates, that you should switch to special heat treated pushrods from the older engine or from crane. I thought I read somewhere that the 3400 pushrods were different lengths and you'd have to get custom ones made. I'm installing the heads this week though. Do you think I should worry about the pushrods wearing prematurely? About all I can do at this point is put plenty of engine pre-lube on the guide plates.

[SappySE107]

The newer pushrods aren't heat treated since they didnt need the metal guides. With metal guides, you probably will run into a problem with wear against the guides. I don't have a clue as to what extent, but if its not advised, I wouldn't do it. Crane can make a set pretty fast from what I remember.

[v6h.o.]

aaron did you make sure you have clearance between the guide plates and the pushrods??

i know on the gen2's with a 1.6:1 ratio you MUST grind out the "U" groove the pushrod sits in on the guide plate for clearance between it and the pushrod, otherwise you have the pushrods grinding against the guideplate untill the guide breaks in two.
with the 1.6:1 stock 3400 rockers i'd check this, as the stock guide plates from the GEN2 engines have a 1.5:1 ratio rocker which has the pushrod sit further away from the groove of the guide.

go to www.pushrods.net they can do custom pushrods quickly and for a good price.

[bszopi]

What a broken guide looks like...

[geoffinbc]

aaron did you make sure you have clearance between the guide plates and the pushrods??

i know on the gen2's with a 1.6:1 ratio you MUST grind out the "U" groove the pushrod sits in on the guide plate for clearance between it and the pushrod, otherwise you have the pushrods grinding against the guideplate untill the guide breaks in two.
with the 1.6:1 stock 3400 rockers i'd check this, as the stock guide plates from the GEN2 engines have a 1.5:1 ratio rocker which has the pushrod sit further away from the groove of the guide.

go to www.pushrods.net they can do custom pushrods quickly and for a good price.

When we (me and Lloyd) put the Crane rockers on his 3.1L we never had clearance issues.

[AaronGTR]

Well, since the heads aren't on the car yet, I obviously haven't checked pushrod clearance yet. I'm in the process of tearing the engine apart right now, and I was planning on having all the things I'm working on done and have it out by thursday. I can take longer if I need, but my parents are gonna be p!$$ed. Oh well. I guess I need to get specs on my pushrods and see how fast they can make a heat treated set and how much it'll cost me. Wish I'd known about this sooner. I keep spending more and more money on this project.

[v6h.o.]

aaron did you make sure you have clearance between the guide plates and the pushrods??

i know on the gen2's with a 1.6:1 ratio you MUST grind out the "U" groove the pushrod sits in on the guide plate for clearance between it and the pushrod, otherwise you have the pushrods grinding against the guideplate untill the guide breaks in two.
with the 1.6:1 stock 3400 rockers i'd check this, as the stock guide plates from the GEN2 engines have a 1.5:1 ratio rocker which has the pushrod sit further away from the groove of the guide.

go to www.pushrods.net they can do custom pushrods quickly and for a good price.

When we (me and Lloyd) put the Crane rockers on his 3.1L we never had clearance issues.

hmm. with Comp Cams Magnum 1.6:1's you do i know that. possibly the cranes dont need this done.

[v6h.o.]

Well, since the heads aren't on the car yet, I obviously haven't checked pushrod clearance yet. I'm in the process of tearing the engine apart right now, and I was planning on having all the things I'm working on done and have it out by thursday. I can take longer if I need, but my parents are gonna be p!$$ed. Oh well. I guess I need to get specs on my pushrods and see how fast they can make a heat treated set and how much it'll cost me. Wish I'd known about this sooner. I keep spending more and more money on this project.

its always the "nickle and dime" stuff that kill's you on projects...
it adds up too quick!!

[AaronGTR]

I found out that crane can make custon pushrods as well. Since they designed the rockers I'm using, and they probably have all the specs for the pushrods I'd need as well, do you think I should order them from crane. I'm sure Smith Brothers could do it as well, but I don't know what the exact radius of the ball ends are. I might have to send them a sample part so it would take even longer.

[v6h.o.]

the ball ends are just regular chevy ball ends. when i called up smith bro's to do a set for a customer one time, i just let them know what diameter pushrod. the lenth i needed and the ball end i just said "regular chevy style ball end" they made them perfect.

i doubt crane will know what lenth of pushrod you'll need. your going to have to tell them. just look in the service manual for the spec. should be 6inch exh and 5.850? (or is it 5.75??)intake?? double check that i could be wrong on the intake lenth.

[AaronGTR]

The service manual lists the exhaust as 6.0" and the intake as 5.68". However I measured them and total length (from ball end to ball end) was 6.125" exhaust and 5.75" intake. Basically 1/16" longer each than what the manual said.

How much did they charge you for the custom set?

[RidgeRunner]

6"-6.125" is 1/8 inch, not 1/16th.

[bszopi]

1/16" longer on each end...

[bszopi]

Here is an explanation of why the lengths may be different...

http://www.compcams.com/Technical/Catalogs/106-03/HTML/306-307.asp