2003 Acura TL I’m in the market for a j35a3 swap, nothing fancy for now just wanna get it running again. Where would I look for a new engine and since I’m gonna get a mechanic to do it would I need to order it through them or do they install customer supplied engines? Any other tips or advice helps

 

Here's an expensive one from a reman vendor:
Premium 3.5L Honda Engine GPT5NN47A36AA - Go Powertrain LLC (go-powertrain.com)

Here is a cheaper example on ebay, though it does not look like they ship:
Acura MDX J35A3 3.5L SOHC Remanufactured Engine 2001-2002 | eBay

Or go the cheapest 'roll the dice' route and get one from a salvage yard in your vicinity by searching car-part.com.
01-02 Acura MDX.

 

+1 Roll the dice is right with used motors.

Don't forget the J35A4. Or swap the internals with j35 crankshaft and rods in j32 block.

 

What about the trans

 

What about it?