Which pushrods for a 3.4/3400

[Canyonero]

What pushrods do I need for a 3.4/3400 hybrid. Does one or the other work or do I need to get specific lengths?

[bszopi]

This should answer it... http://60degreev6.com/forum/showthre...ybrid+pushrods

[Canyonero]

This should answer it... http://60degreev6.com/forum/showthre...ybrid+pushrods

Hm, clear as mud.

Is this the answer? That conversation drifts in and out of 3400 and 3500 references...

pushrod guides are needed for only early 3x00 heads, after that they wnet to non-adjustable roller-fulcrum rockers,

use 93-95 3x00 rockers, studs, pushrods and guides for later heads (I have a set of modded guides if you use 2000+ heads),

Iron head studs and rockers will bolt right into heads up to 2000

What classify as "early 3x00 heads"? Mine are from a 97-98. Since that is before a 2000, can I use my iron head studs and rockers? Then I still have to find some pushrods and guides from what?

[bszopi]

The early 3x00 heads are 93 to mid-95, when they came stock with stamped rockers (and therefore guide plates). I'm not 100% sure on the iron head rockers, but I would probably look for the 3100 stamped rockers, as they are 1.6 ratio versus the iron head 1.5 ratio. And as stated above, use guides from 93-95 3100 (NOT 3.1, as it was still available in certain applications).

[Canyonero]

But if I want a Crane H-260-2 Cam, I should stick with 1.5 ratio, right?

http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=6&Engine_Make=CHEVROLET&Year=1986&Engine_Size=2.8-3.1%20L&partNumber=253901&partType=camshaft

[ForcedFirebird]

But if I want a Crane H-260-2 Cam, I should stick with 1.5 ratio, right?
http://www.cranecams.com/?show=brows...tType=camshaft

No, you don't have to as long as the springs you are using can handle the lift of your cam (remember to multiply the lobe lift by 1.6 instead of 1.5).

I used pushrods from a 1991 Cavalier 3.1, and measured them multiple times to make sure they work. I came up with the same preload as a stock 3x00. I got the idea from Russell, he's been running them in his 3.4/3400 hybrid since 2001(?), and it's a daily driver.

That thread was erlier and I was going to try and use some 1.7 rockers I have extra from a Ford, but then the ushrods would have had to be so long, that there would be even MORE clearance problems between the LIM and rockers than using the Crane Gold's.

[bszopi]

As long as you checked everything out, I'm sure you'd be fine. More lift is never a bad thing, until components start hitting each other. I am pretty sure that there are people out there running a 260 grind with 1.6 rockers, so it shouldn't be an issue.

[Canyonero]

I feel like a noob again, not knowing which components to mix and match. I'm sure it will be worth it, and I appreciate everyone's patience.

Is there a particular spring that would be best, assuming a 260 grind and 1.6 ratio? Seems like all the serious guys are using LS1 springs.

Thanks!

[IsaacHayes]

Correction, early 3100 heads had stamped ball pivot fulcrum rockers. ALL 3400 had roller rockers.

Your heads (are they 3100 or 3400?) have the notches so you will use the roller rockers on them.

LS6 springs are better than LS1. Go with those. Not sure about that cam if you need stronger than that. So you'd have to find out from someone else, but the LS6 are stronger than LS1's. The LS1's are just a little bit better than stock 3x00 I hear.

Does anyone know if he can use roller rockers? Why the suggestion of using the older 3100 stamped ball/pivot??? Should be able to use the roller rockers just fine right? I don't think the bottom end affects the need to use push-rod guides just the rockers right? Hell you could probably use the old 3100 guides and hardened push rods and the roller rockers up top maybe? But no need with the roller rockers I thought?

[ForcedFirebird]

Does anyone know if he can use roller rockers? Why the suggestion of using the older 3100 stamped ball/pivot??? Should be able to use the roller rockers just fine right? I don't think the bottom end affects the need to use push-rod guides just the rockers right? Hell you could probably use the old 3100 guides and hardened push rods and the roller rockers up top maybe? But no need with the roller rockers I thought?

If there are notches in the heads, use the roller rockers, if not, then stamped is the only choice (unless the heads are machined for the slot). Correct, the rockers will dictate weather or not guides are needed - stamped rockers need a way to stay straight. He has to use pushrods from a non-roller block (ie the 3.1 MPFI Cavi I mentioned).

Yes, there is a thread here somewhere that Ben listed all the LSx springs he had tested - IMO yellow springs (LS6) are the best bang for the buck, but requires a little modding to get them in.

[bszopi]

Well, considering the 3400 didn't debut until 1996, it is still correct to say 93-95 3x00s had stamped rockers.

[IsaacHayes]

Ok, so roller rockers, no guide plates, 3.1mpfi pushrods, and then a spring that will handle his cam and he is set then right?

[ForcedFirebird]

Well, considering the 3400 didn't debut until 1996, it is still correct to say 93-95 3x00s had stamped rockers.

The question is, though, are the slots for the roller rockers in those heads? Some people have been lucky to have them, others don't. Do we know if there is a dividing line for the slots (as far as years)?

[Canyonero]

My heads have notches. I'm told my heads and LIM are from a 97-98 van of some sort. The rest of the stuff I have is from an '02 Grand Am.

If I'm looking for roller rockers, am I back to 1.5 ratio, or can I get either?

[IsaacHayes]

ALL 3x00 have 1.6:1 ratio. You can use rollers on those heads, and if they are from a van they are 3400 so you have the larger intake valves too.

If that year is right on your heads you need the rocker studs from a pre 2003 head (I think thats the year it went from 10mm to 8mm)



FF: All 3400 got the roller rockers. Some 95 3100's had the notches but didnt have rollers. All 96 had notches I think and some got rollers some didn't. By 97 they all had rollers I think.