Im switching from a cc304 to gm847 on ported heads so I will be upgrading the valvetrain. Crane 99893s with kmotion 10degree locks and retainers.

The crane dual springs are 1.46OD. Im thinking of getting the comp cams 4771 spring locators: .060 in.Thick, .570 in.ID., 1.55 in.OD., .690-ID.Spring

some questions have been bugging me:

1) will i need to machine the seats on my 95 lt1?
2) If so, can it be done with CCA-4719 Spring Seat Cutter (1.550 cuts Guide .630)?
3) Do the heads need to be removed to cut them?
4) Is there a spring seat locator (not shim) that can fit these springs AND the stock valve seats (i.e. no machining required)?
5) Will GM stock valve stem seals work with these dual springs?

Thanx guys. Ive seen several conflicting answers on searches.

 

I would say go with the Comp beehive springs and leave the seats alone. The
only machining you will need to do is on a set of spring locators. This is the info
from a previous post.

Comp beehive springs (26915 or 26918) information for a stock LT1 aluminum head:

Comp parts
26915 springs
795-16 retainers (for 10* super locks)
614-16 super locks (+.050")

Manley parts
42437-16 CNC .062" thick spring seats (w/ OD machined down to 1.32")

The installed height of the spring with this setup was 1.745". If
you use the 7* hardware your installed height will be .015" less,
or 1.730". If you really wanted to get more installed height you
can machine down the thickness of the seat to obtain your target
installed height. I looked all over the place to find an off the shelf
spring seat that would work and ended up with the Manley's. I
had a machinist friend cut down the OD of the seats from 1.570"
to 1.320".

If you want more spring pressure go with the 26918s. The beehive springs
are good for .600" lift when installed at 1.750" or more.

 

i already have the crane springs, in my possession.

So i still need to know if i can find a valve spring locator that will fit these springs and not require machining of the heads. And if its possible to machine the heads while they are on the car, i imagine that would be tough.

Still wondering if stock gm valve seals will work with dual springs, and if they are the best option in terms of quality. Basically, all my questions above

 

[QUOTE=truedualws6]

Manley parts
42437-16 CNC .062" thick spring seats (w/ OD machined down to 1.32")
QUOTE]

BTW Comp has some locators that drop in WITHOUT MACHINING!

Bret

 

I had asked once before in a response to another post what the Comp part
number is for these seats. I called Comp and they did not know what I was
talking about. I am really interested in the specs of the Comp seats.

 

[QUOTE=SStrokerAce]If the OD of the seat is 1.32", and the OD of the spring is 1.46, is that ok? Sorry if its a dumb ?, i dont even know what these parts look like yet. I figured the spring locator is like a cup that the spring sits inside.

Otherwise i could use l98 valve spring seats which i believe are 1.32" OD

 

anyone know about valve seals?