I'm not planning to do it to my car, but for those who really want a V8, wouldn't the LS4 bolt right up to the 4t65e? I know it bolts right up to a getrag 282 tranny and don't the 3800's bolt right up to them as well?
The LS4 might have a bad manifold and whatnot but they have LS6 heads and can probably be taken out of a junkyard from a Impalla SS, monte carlo or pontiac G8 late year model for cheap
And for a manual transmission, couldn't you use the LS4 mated to a GM F40 six-speed transmission found in the Pontiac G6, and use a donor G6 junkyard subframe to mount it?
I'm not sure on all the details like engine clearances or how the shifter linkeage would work, but I'm just throwing that idea out there for people who want a V8 or manual transmission.
Also another thing I'm actually very interested in is how much power can you actually put in a GM F40 transmission, and if you had it cryo treated and whatnot, could you put more power in it?
Like i said, not really trying to do this to my buick but I was toying around with the idea of something like an LS4 fiero with an F40 transmission
I know they sell kits for the G50 tranny out of a porsche which can handle huge amounts of power but you can get an F40 tranny off ebay brand new for like $400 plus freight shipping whereas the G50 would cost probably 6 times as much.
http://www.ebay.com/itm/G6-6-Speed-Manual-Transmission-0-Miles-F40-Trans-/251157968650?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a7a2e770a&vxp=mtr#shId
Anyway just throwing some food for thought out there and trying to get an honest opinion on the F40 transmission's capabilities
EDIT:
seems like you can get an LS4 for under a grand on ebay as well :
http://www.ebay.com/itm/CHEVROLET-IMPALA-Engine-5-3L-VIN-C-8th-digit-12H0820-2006-/380492172557?pt=Motors_Car_Truck_Parts_Accessories&fits=Year%3A2006%7CMake%3AChevrolet%7CModel%3AMonte+Carlo%7CSubmodel%3ASS%7CEngine+-+Liter_Display%3A5.3L&hash=item589719cd0d&vxp=mtr
