Selling my BMW 325XI, has used engine with less miles, what should I expect for a good price?

I am trying to trade in my 2002 325XI. The engine blew so I put in a used engine with some 30,000 less miles than the first. The engine in there now has 62K miles. Will this affect the price that I can now sell it for? If so, how (good or bad)? The car is in good condition, not great. The car itself has 92K miles Does it even matter how many miles the new engine has? Obviously I cannot examine the odometer on the engine myself... I don't even know how tho it would be nice to look at since I didn't see the engine before it was installed, but it runs great and I even had it checked by a BMW dealer who said it was running very well and was installed correctly. I want to trade it in but I do not know how having a used engine with lower miles than the car will affect the amount that I should expect to get for it. The kbb only says it's worth like $7,200 whch means I really got scammed because I bought it for $12,000 and it had serious mechanical issues which is why the engine blew after only 2 months of owning it. I've now owned it for 5 months but only drove it for 2, I put 5K miles on it. Any ideas? Thanks!