For the heck of it, here’s the make up of some Lytton Springs I tasted recently:
'87 Lytton Springs (Dry Creek Valley)
(82% Zinfandel, 13% Carignane, 5% Grenache)
1990 Ridge “Lytton Springs”, Dry Creek Valley
(80% Zin, 10% Petite Sirah, 6% Carignane, 4% Grenache)
1991 Ridge “Lytton Springs”, Dry Creek Valley
(80% Zin, 12% Petite Sirah, 5% Grenache, 3% Carignane)
'92 Lytton Springs (Dry Creek Valley)
(88% Zinfandel, 8% Petite Sirah, 4% Grenache)
'93 Lytton Springs (Dry Creek Valley)
(85% Zinfandel, 3% Carignane, 2% Alicante, 2% Grenache)
1994 Ridge “Lytton Springs”, Dry Creek Valley
(80% Zin, 13% Petite Sirah, 4% Carignane, 2% Grenache, 1% Alicante Bouchet)
1995 Ridge “Lytton Springs”, Dry Creek Valley
(84% Zin, 14% Petite Sirah, 2% Carignane)
'96 Lytton Springs (Dry Creek Valley)
(78% Zinfandel, 19% Petite Sirah, 2% Carignane, 1% Grenache)
'99 Lytton Springs (Dry Creek Valley)
(70% Zinfandel, 17% Petite Sirah, 10% Carignane, 3% Mataro)
'01 Lytton Springs (Dry Creek Valley)
(76% Zinfandel, 17% Petite Sirah, 7% Carignane)
'02 Lytton Springs (Dry Creek Valley)
(75% Zinfandel, 20% Petite Sirah, 5% Carignane)
'03 Lytton Springs (Dry Creek Valley)
(76% Zinfandel, 18% Petite Sirah, 6% Carignane)
'05 Lytton Springs (Dry Creek Valley)
(77% Zinfandel, 17% Petite Sirah, 6% Carignane)
'07 Lytton Springs (Dry Creek Valley)
(71% Zinfandel, 22% Petite Sirah, 7% Carignane)
There is a pretty good variation there, which you can taste. But they do seem to have stabilized the blend more recently.