Need help identiying 403

[mastersativa]

I just got a 403 to swap out my 350 with and was wondering where to look to find out what exact year it is. i do believe it is early 80's but am not real sure. the reason i would like to know is to get the correct gaskets and plugs and wires and such before i drop it in this weekend. Is there someplace online that i can put in the numbers from the block and it will tell me what i got? any help would be appreciated, thanks.

 

[3XBrownCutty]

i would just google the casting on it. i believe the 403's were only made a select few years.

http://www.442.com/oldsfaq/ofblk.htm

 

[Blake442]

403's were only produced from '77-'79, so that oughta narrow it down.

There is a small pad by the #1 cylinder, just below the head that will have a series of numbers stamped in it.
It may be covered in grime, but those numbers will tell you what you need to know, provided they're still there...

 

[mike87442]

Just look at the casting number on the top of the block behind the timing cover right where the oil sending unit screws in if you have a standard 403 block the number will be 557265-4b and if you have a number of 557265-4a or 554990-4a you have a rare "Solid main web block", I doubt that you have this one as only 2500 were made.Also all 403 blocks have a "403" cast in the side of the block. 403's were used in various GM vehicled produced from late 1976 to 1979 from Pontiac Trans Am's to Buick wagons

 

[joe_padavano]

Just look at the casting number on the top of the block behind the timing cover right where the oil sending unit screws in if you have a standard 403 block the number will be 557265-4b and if you have a number of 557265-4a or 554990-4a you have a rare "Solid main web block", I doubt that you have this one as only 2500 were made.Also all 403 blocks have a "403" cast in the side of the block. 403's were used in various GM vehicled produced from late 1976 to 1979 from Pontiac Trans Am's to Buick wagons

Have you ever wondered how, if 2500 of the mythical SMW 403s were really made, no photograph or other proof of existence has ever surfaced in the last 30+ years? I have one of 912 69 H/Os, one of the 1700 1966 tripower intakes, even one of the handful of experimental factory cross ram intakes, but no one has ever seen a SMW 403. I don't care what Mondello says, the SMW 403 doesn't exist.

 

[mastersativa]

Thanks for the quick response, i have the 4b engine but cant get to the numbers on the side of the block at the moment. But if they only made them the three years chances are all the gaskets and tune up parts will be the same. Thanks again.

 

[joe_padavano]

But if they only made them the three years chances are all the gaskets and tune up parts will be the same. Thanks again.

They are.