390 service block date code location
 

'67 bird with a 390 that I am trying to get running, after changing out dist and carb, I had problems getting it started. I was a tooth off on the distributor, restabbed that and was checking fluids when I got the dreaded chocolate milk dipstick. I have pulled the heads off and they are C8AE-H. The intake is the right S code late '66.The block date code is 5k26 so it could be Oct 26, 1965 or 1975.
I can't find a decade code on the block, the rear plate on the drivers side is blank, any other locations I should de-crud next--I think I just created this cars nickname, "de-crud mobile". Thanks Dave

Here's a good article that explains block casting numbers. The date code should be near the oil filter mount.

Deciphering Ford Parts Date Codes - FORDification.com

Based on your 5K26, the date is 19_5, October 26. The C on the head signifies the decade, 60's, so your engine was cast on October 26, 1965.

Since the model lines came on in the prior September, your engine was made for a '66 vehicle.