This one is a battle of the Titans.
The Big Block Stage 1 High Performance 400 engine was introduced in the 1969 Buick GS400. The brain child of legendary Buick Powertrain engineer Dennis Manner, the Stage 1 produced 345 hp. It featured a high-lift cam, 11.0:1 compression heads (instead of 10.25:1), a larger carburetor, specific fuel pump, and larger low-restriction exhausts. Like all '69 GS400 models, the hood scoop was actually functional and part of Buick's Cold Air Induction system. Dennis' mantra was "Fast for the Street", so the engine developed huge amounts of low end torque in order to launch away from the stop light.
The T-Type was a child of a different era. Lloyd Reuss developed the V6 as an economical powertrain and put a turbocharger on it in 1978 in order to provide performance more befitting a V-8. Despite pacing the 1976 Indy 500, the Buick V6 wasn't regarded as much of a performance engine until 1984, when a SFI version produced 200 hp. The Grand National was introduced that same year, and the performance hit its peak when the Intercooled version was introduced for 1986-87. Buick released a performance figure of 245 hp, but it is widely known to be understated, and is net hp compared to the gross rating of the '69.
So now our unscientific test- both cars are modified but street legal, so it's really just for fun. Can a little turbo 6 stand up to a 400 Stage 1?
Just remember they don't call it the 'little engine that could" for nothing.