Not sure which route to take

[Ckjackson]

I have a 1995 318ti with roughly 210k miles. I got the car with intentions to build with my 8 year old daughter and pass it down to her once she starts driving. I went and paid 200 bucks on a 1993 325is. My plan was to take the interior out of the 325 since it is black and put in 318. I am torn whether to build the m42 and turbo it or put in the 2.5. What other parts can transfer over to the 318 besides the front brakes?

[Biolite]

I think pretty much anything from the transmission forward could be transferred over. With the engines, there may be a larger aftermarket available for the M50 engine over the M42 since there are/were more sold. So you may have more options that way in building the engine. Just something to think about.