An N52 shouldn’t be 2K less than an S52. Either you’re looking at overpriced s52 or dirt cheap/questionable N52. For comparison my full s52 dropout from e36 M3 was 2100 with 130K. I’ll attach a FB post of one. Check more popular forums or even CL.
The m54b30 can also be modified for more power with the typical bolt ones, etc. I’ve seen full cars for $1000 with that motor so far less than other options. Basically any e30,e36 trans bolts up.
A lot of this comes down to money,skill level and time. Are you going to be doing this yourself? Are you wanting to learn from this? Or will you be dropping this off for a shop to build?
I recommend getting as much information from what you want out of it and go from there. Ie, is this something you want to drive soon, etc. an S52 is bolt with some simple wiring modifications.
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