Anyone in here switched there intake over to a series 3 aluminium intake its being done with one big change a 3 bolt TB adapter to 4 bolt TB so the series 2 TB can be used I have seen images of this but cant seen to lock down that adapter unless its the ls4 3 to 4 bolt adapter shown in link ICT Billet 551567 Throttle Body Adapter, 4 Bolt to 3 Bolt | eBay none say that they are for the 3800 3 to 4 bolt but someone has them or its the same one because I have seen this done the weak link in the 3800 is the intake and if I can get switched to the series 3 that will be great

I have only seen a couple that have done it. Sleeved intakes greatly extend service life, or, others have even just plugged it entirely.

The sleeve intakes usually fix it good enough that it'* not the weakest link any more. Remember, even the Aluminum framed LIM gaskets (which you should also look in to if you haven't already) have a limit to their service life.