I went to the junk yard yesterday and found a few good engines with the original intake manifold fasteners on them. First off I ran across a 1965 "HB" coded block. 327/300 HP four speed HP engine in an old Chevy pickup. The intake manifold bolts had the "C" and "M" head marks. I harvested all 12 and now are soaking in a bucket of Simple Green. I then ran across a 68 Impala with the "HJ" stamped block. 327/250 four barrel PG engine. This engine still had the original lifting hooks with the "shouldered fasteners". The shouldered fasteners had "FP" head marks. Most of the intake manifold bolts had already been removed from this intake manifold but I did remove one which was coded "CS" inside a circle with three radial lines. Lastly, I ran across a 67 four door Chevelle. This car had the 327/275 PG with AC installed. I was running out of time so I just took one intake manifold bolt out of it and it was a "M". I also got a decent 834 alternator with a Jan 20 1969 date code from the 65 Chevy Truck. Went to Autozone to test it and it passed. Pretty funny....So in summary I am going to put on the Silver car the "C" head mark intake manifold fasteners that came in a box with other parts. I am guessing these were on the car originally. When I got the car the engine had just been rebuilt and the engine shop used new fasteners on the intake.