I am pulling out one motor to switch out for another v12 just wondering if anything needs done before I place the motor in the car

 

How much do you know about the "new" engine?
Did it have any leaks before it was pulled?
If it still has its original gaskets (valve cover, oil pan, cam plugs etc.) I would highly recommend replacing those before installing the engine in the car. Much easier to do now than later.
Same goes for all of the vacuum lines and heater hoses. Many of them are routed under the intakes and difficult to reach with the engine in place. Replace those parts now!

Also, What is the condition of the Rack and Pinion, Oil Cooler, AC Valve? Again...sooooo much easier to service those things when the engine bay is uncluttered by a V12. ;-)

How about the Ground straps and battery cables that go to the starter and alternator? Again, if they are old replace them now. Muuuuch easier to access.

Basically, look at everything in the now empty engine bay. Replace and repair everything you can. You life will be so much easier to do it now and you will have peace of mind that the car will be reliable for many years to come.

Mark

 

Big job by anybodies measure. Unless I were absolutely 110% sure of the donor engine, I would want to consider at a minimum replacing the timing chain tensioner while I had engine out. Would recommend water pump replacement/rebuild as well. MUCH easier with engine out.

 

Anything easy to get to, any kind of oil seal, especially the banjos. I'd probably consider putting in freeze plugs in it unless the inside of coolant pipes looked really good. The rubber plug for the timing chain, water pump, definitely anything on the firewall like heater hoses and valves. Obviously rear main seal and the front seal on the trans.

Just look at the top of the engine, what you would normally see, and look at all the things you can't get to and clean and replace if it is that type of item. Maybe consider changing to a new alternator and replace oil hoses, the list goes on and on.
Clean EVERYTHING while you can.

 

yes it is a big job I do little parts and I walk away and come back to it or else I would go insane