im getting a 13b swaped into my 94 rx7 and found 2 engines to possibly
swap into my FD. one with around 40k orig miles for 4280$ and one with around 56k miles for 3000$, kinda straped for cash right now what should i choose?

 

Get a compression check on both of them.Then go from there.

 

Take Chris's advice. "Miles" don't matter quite as much as how those miles were treated.

I have over 300k on my 944 turbo that is stock, it runs better than many with half as many miles.