351W - with some Q's

[Unit 5302]

If the cooling system in place is functioning properly, the 351 will be fine.

Take a look at the block for casting numbers. Those numbers will tell you what year the block was manufactured.

i.e. C8 = 1968.

C being the decade

60's C
70's D
80's E
90's F

8 being the year in that decade.