By the way, the more I see you complete on this build, the more I wanna take a crack at it myself. Seems a whole lot simpler than fongooling with blow thru.
Glad I could help some. I can't find any specs on his motor much other than he runs two holley450s and what is listed in the thread. I calculated his HP roughly with the weight of the car he provided and it came up as close to 350. :D
Here's something to see Ed. Maybe this will help some. This guy is ran a best of 11.15@120MPH
http://www.slantsix.org/forum/viewtopic.php?t=5432&start=0&postdays=0&postorder=asc&highlight=
I didn't take that into consideration that the *-71 series blowers are giant heat pumps. The disadvantage of the M-series is where do you put the carb or is there some kind of adapter available to run on that style of blower?
The supercharger off the Grand Prix GTP is a funky pattern. Its not really close to the 4-71 pattern. The M90 blower isn't too hard to come by out here. Plenty of fried GTPs with blown headgaskets.