1974 LS4 - Pushrod Question
Thread Starter
Advanced
Joined: Mar 2010
Posts: 78
Likes: 0
From: Houston TX
1974 LS4 - Pushrod Question
Prior to my purchase, the engine was just recently rebuilt to fully stock parameters, and in the process one of the rockers was overtightened and resulted in a bent pushrod.
So NOW, I'm working on replacing the pushrods, but the parts store tells me that they have two different diameters listed for my model year. The ones they said would be the best match are spec'd:
.310 inch
8.28 inch
and
.310 inch
9.252 inch
What exactly ARE the stock dimensions? Do I need to worry about the guides?
On that same note, I noticed that it looks like some of the rockers are 'shinier' than the others. I get the feeling that several have been replaced in the rebuild - they look to be the same overally, but is this okay, or do I need to replace all of them to be certain there are no differences.
Fun stuff!
So NOW, I'm working on replacing the pushrods, but the parts store tells me that they have two different diameters listed for my model year. The ones they said would be the best match are spec'd:
.310 inch
8.28 inch
and
.310 inch
9.252 inch
What exactly ARE the stock dimensions? Do I need to worry about the guides?
On that same note, I noticed that it looks like some of the rockers are 'shinier' than the others. I get the feeling that several have been replaced in the rebuild - they look to be the same overally, but is this okay, or do I need to replace all of them to be certain there are no differences.
Fun stuff!
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,334
From: North of Toronto - Ontario
Prior to my purchase, the engine was just recently rebuilt to fully stock parameters, and in the process one of the rockers was overtightened and resulted in a bent pushrod.
So NOW, I'm working on replacing the pushrods, but the parts store tells me that they have two different diameters listed for my model year. The ones they said would be the best match are spec'd:
.310 inch
8.28 inch
and
.310 inch
9.252 inch
What exactly ARE the stock dimensions? Do I need to worry about the guides?
On that same note, I noticed that it looks like some of the rockers are 'shinier' than the others. I get the feeling that several have been replaced in the rebuild - they look to be the same overally, but is this okay, or do I need to replace all of them to be certain there are no differences.
Fun stuff!
So NOW, I'm working on replacing the pushrods, but the parts store tells me that they have two different diameters listed for my model year. The ones they said would be the best match are spec'd:
.310 inch
8.28 inch
and
.310 inch
9.252 inch
What exactly ARE the stock dimensions? Do I need to worry about the guides?
On that same note, I noticed that it looks like some of the rockers are 'shinier' than the others. I get the feeling that several have been replaced in the rebuild - they look to be the same overally, but is this okay, or do I need to replace all of them to be certain there are no differences.
Fun stuff!
M
]
Thread Starter
Advanced
Joined: Mar 2010
Posts: 78
Likes: 0
From: Houston TX
I'm assuming that's not a show stopper for me?
As to proper install procedure I keep finding conflicting info - all sources say to tighten rockers to the 0 lash point by going until the pushrod no longer has and spin/play. But from there I've seen some say take it a 1/2 turn more, some 3/4 and a full... Which is real here?
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,334
From: North of Toronto - Ontario
I just pulled the ones that were in it, and the seem to be just slightly shorter on the intake side than the dimensions of the ones on order, about .15inch less roughly.
I'm assuming that's not a show stopper for me?
As to proper install procedure I keep finding conflicting info - all sources say to tighten rockers to the 0 lash point by going until the pushrod no longer has and spin/play. But from there I've seen some say take it a 1/2 turn more, some 3/4 and a full... Which is real here?
I'm assuming that's not a show stopper for me?
As to proper install procedure I keep finding conflicting info - all sources say to tighten rockers to the 0 lash point by going until the pushrod no longer has and spin/play. But from there I've seen some say take it a 1/2 turn more, some 3/4 and a full... Which is real here?
As for setting the lifters, it's all doing the same basic thing, some people set them shallow, some deep.
If you want, send an email to Lars (v8fastcars@msn.com) and ask for his paper on setting valve lash and make your own choice
M
Last edited by Mooser; Apr 26, 2014 at 07:59 AM.
