New Guy in San Jose could use help

[SanJosesSteve]

Hello Everyone,
I've been the proud owner of a 59' GMC Stepside for about 15 years now. Gramps bought it brand new and only clocked 92K on it before giving it to me. I've put another 30K on it as a weekend driver. It's bone stock. 270cid, 3 on the tree, and never had so much as a radio installed. (Still has the speake r and head unit blanks installed.) Motor never opened up.
Anyway, it's rear crankshaft seal has been M.I.A. for years now, and has trouble maintaining oil pressure w/o a generous helping of Lucans Oil Stabilizer. Recently I noticed some water in the oil. Changed the head gasket but the problem did not go away. I'm thinking the head may be cracked or worse.
Anyone have a reccomendation for a machine shop in the SF Bay Area? I hate to take it just anywhere. I don't imagine shops see GMC 270 Straight Six's every day.
Any advice appreciated. Thanks -SF

2005 Ford Five Hundred
2000 Jeep Cherokee
1972 Fiat 124 Spider
1959 GMC Stepside