Need help with ID Plate and engine Ser #

[oldguy64malibu]

I have a 1964 Malibu convertible, base model.
1. The engine stamping located at the front right corner is F0514J. I think this means it came from Flint Mi. on the 5th month and 14th day. The J I think stands for a 3 speed manual transmission. The engine is a 283 2 barrel carb.
The transmission and steering column now are a Powerglide setup. My guess is that this engine is not the original engine but
wonder how do I find out what exactly this engine is.
The ID Plate on the cowl, firewall, has a grouping of letters & numbers that I cannot figure out. They are as follows,
W 2P S 3C 5W.
2. Is there such a thing as numbers matching engine block and body for the 64 Chevelle ?
Thanks again for all your help.

[shadowgray396]

W Tinted windshield
2P Comfort & Convenience group - Type A [RPO Z01]
S Rear antenna [RPO U73]
3C Padded dash [RPO B70]
5W Custom deluxe seat belts with retractors [RPO A49]

The numbers in from of the letter is the group number.

[oldguy64malibu]

Thanks a lot for the quick response. The car still has everything you mentioned except for the retracting seat belts. I guess they must have given up the ghost sometime in the past.