hi Guys
im in the middle of installing the valve springs in my 781's. I have the rotators in the exhaust side. Im using cc 930-16 spring and the inner spring is riding directly on the ridge of the rotater. Since ive never assembled a set of bbc's before im unsur if this is normal or not.

Jester,

The 930 spring is a double spring and cannot be used with the rotators.

You need to step back and take a look at a couple of things.

1. Were your stock springs all the same height, or were the exhaust springs shorter than the intake springs ? If the springs were two different lengths, you will probably just have to discard the rotators.
If the springs were different lengths, you will have to get a set of Comp's rotator eliminators which are just solid blocks that go in where the rotator was.

2. If you are using those springs, I am sure you are going to a larger camshaft too. You need to check if the valve will open enough without the retainer hitting the top of the valve guide, or the seal. I am betting it will not and the top of the guides will have to be machined.

3. Will you valve seals fit inside the inner spring ? The Big Block stock guides are pretty big and almost always need to be machined for small positive type guides.

I think you need to post some more information as to what heads you have, any modifications that have been made to them, what cam you are running, etc ..... before you go any further.

Jester,

The 930 spring is a double spring and cannot be used with the rotators.

You need to step back and take a look at a couple of things.

1. Were your stock springs all the same height, or were the exhaust springs shorter than the intake springs ? If the springs were two different lengths, you will probably just have to discard the rotators.
If the springs were different lengths, you will have to get a set of Comp's rotator eliminators which are just solid blocks that go in where the rotator was.

yes the springs are the same height and installed height was 1.875"


2. If you are using those springs, I am sure you are going to a larger camshaft too. You need to check if the valve will open enough without the retainer hitting the top of the valve guide, or the seal. I am betting it will not and the top of the guides will have to be machined.

3. Will you valve seals fit inside the inner spring ? The Big Block stock guides are pretty big and almost always need to be machined for small positive type guides.

yes already machined for small seals and do fit inside the springs


I think you need to post some more information as to what heads you have, any modifications that have been made to them, what cam you are running, etc ..... before you go any further.

781's stock size vavles (manleys)
gasket matched intake with slight bowl work
comp 294B solid 256/266 .580/.605lift 108lobe sep
427 ZL1 pistons 7/16" rods std std
vic jr.
850
stamped rockers

Jester,
Sorry for the late reply, I have been working on the house all day and just turned the computer on :( If your springs were all the same. and everything else looks like it will work ok, then you need the rotator eliminators. If you can wait a few days, I have two good used sets of them, I can send you one cheap.

Jester,
Sorry for the late reply, I have been working on the house all day and just turned the computer on :( If your springs were all the same. and everything else looks like it will work ok, then you need the rotator eliminators. If you can wait a few days, I have two good used sets of them, I can send you one cheap.
sure let me know before i order a set.
Ps do you have an intake oval vicjr laying around?