Hey Guys,

Haven't posted on the forums in ages... This said its time to ask some questions. I have 2003 discovery that I have spent the last few years getting back into good mechanical shape. Unfortunately my 4.6 that was poorly rebuilt by the previous owner has started to grenade on itself. It has a distinctive nock until the engine gets up to operating them then still has a faint nock. Anyhow previous owner didn't do me any favours, in fact probably would have been easier had he not touched it in the first place. This said The truck has run for the last 10k miles without a check engine light and has been incredibly reliable since I finally got her on the road. Here is the list of things I did to the 4.6 engine:

-oil pump and front cover rebuild
-water pump
-timing gears and chain
-180 thermostat (new rad, all new hoses)
-$1000 new old stock ecu harness (lets not even go there)
-new injectors
-new plugs, wires
-4 new o2 sensors, new maf
-power steering pump rebuild
-new temp sensor
-new pulleys and tensioner and belt

Basically have a good new proven reliable setup but with a bad motor. Luckily for me I picked up a parts truck (2000 discovery) a few years back and stocked up on parts for the future.

My plan in the near future is to get a 5.3 setup that we have all been drooling over on lucky8's Instagram the last few weeks but for now I want a "good" engine for the summer.

So I have a 2000 4.0 engine (100k miles) that sounded great when I pulled it and ran good temps etc. I plan on doing a refresh on this engine before I swap it in and use the good "newer" parts of my 4.6 to bring it back to life.

I would like to do all the seals, head gaskets on this engine and basically pop it in but I'm looking on advice on what I should do and what parts to swap, keep, rebuild, etc.

I was thinking of getting the lucky8 head gasket kit and all seals to start with.

Should I keep my refreshed front cover from my 4.6 or should I rebuild the 4.0 front cover?
Should I swap my fresh heads of my 4.6 or should I simply reuse the 4.0 heads?
If I keep the 4.0 heads, since the head gaskets aren't leaking yet can I simply remove them, replace the gaskets and bolt them back on with new studs or do they still need to be plained first?

What else should i do while its out that could be a PITA later?

Since the 4.6 was attached to the 4hp24 an the 4.0 attached to the 4hp22 which torque converter should I use? is it the same flex plate and fly wheel?

Any sound advice will be appreciated! I will post plenty of pictures of the swap if anyone interested.