Originally Posted by bmwman528e

The 4.4, 4.6, and 4.8 as I'm sure you are aware are maintenance whores. Between timing chain guide failures, vanos repairs, valve seals on the 4.8 not to mention the wonderful tranny problems at anything over 100k miles. They make decent power and are fun to drive with the BMW engines but 400 rwhp is easily obtainable for less than $1200 in modifications to a bone stock LS1. They are simple as pie to work on, give you twice the engine bay space to work on everything as they are not nearly as wide as the BMW engine. Parts can be had at your local autozone for a 1/3rd the price of your BMW parts. LS engines are extremely economical and if geared correctly in my 5 series yield 24-27mpg consistently on the freeway and in an X5 should get over 20mpg as well.

I absolutely love E53, E38, and E39 styling but with our cars getting older it's one repair after another. BMW's crappy plastic cooling system failures, brittle plastic timing chain guides etc.

Outsourcing custom one off engine mounts, headers, trans mounts, shifters etc would all make these swap less enticing price wise but with cheaper mount solutions and a few guys who actually complete the swap to do some trial and error work this is a feasible option for an old tired E53.