Hello,

I just purchased an 87 K5 Blazer that the seller said had a swapped 400 in it. How do I tell for sure which motor is in it, any tell-tale signs?

I am not an expert mechanic, but if you tell me where to look I can figure it out.

Thanks!

 

google Chevy engine identification. theres a particular location on the block that has the engine ID on it. put those numbers into a site on the internet (again, not sure where, google is your friend). That should tell you which motor it is.

 

I agree on the google comment. The block will have two sets of numbers on it provided the decks haven't been cut. One will be the block casting code which is cast into the top/rear of the block behind the driver side cylinder head. The other is the block deck stamping which is on the cylinder head deck just ahead of the passenger side cylinder head. If you google the block casting code, you should be able to find out what that block was used in. The 400 block is different from the 350 blocks due to the siamesed cylinder bores.

 

Alright. It is definitely the 400...any know the spark plug gap?

 

My 73 400 gap is 035 just like your typical 350

 

Alright thanks thats what I thought. I just bought this truck as a project truck, I'm 19 so Im not car expert, but im learning as I go along. So sorry if some of the questions are stupid.

I will definitely be utilizing this forum a lot.