Topic: whitc engine do I have? reading numbers...

[Hammond]

I have a 1977 Trans am SE

The engine is a 400 V8 ( I believe. Correct me if I am wrong.)

but, it seems to me that if I have done my job correctly, I have a 1973 block, with 1977 X6 heads.

Here are the numbers:
Block:
"481988" this is the engine number?(on the rear of the block)
"J253" this is the date? (also on the rear. close to the distributor)
"277429 YH" ( in the front of the engine)

Heads:
"6X" (in the side of the head) should it not say 6x-4 or 6x-8?
"C247" (does this be the date?) also on the side of the head, at rear.

can anybody help me confirm my engine?

thanks...

[Joker (§ir£Ğragon)]

Yes, that is definitely a 400. Build date is "J" = Oct. "25", 197"3". The YH would indicate it was used in '74 (which would agree with the late '73 build date) and was originally a 175/190hp 2bbl engine.

And yes, the 4 digit code on the head is also a date code, read just like the engine date code. "C" = March "24", 197"7".
'77 6X heads have 2.11" intake and 1.66" exhaust valves and 101cc chambers. These are possiblly the original heads for your car and maybe just the short block was replaced.