So with the added weight of the 351 I really dont think it weighs 2700 anymore?? I could be way off though but I dont think it could be 2700 with a 351 under the good because I do know a 351W weighs around 530 pounds with out accessories. Depending on what year 351 you have it might not be as quick as I think, some made as little as 170hp, most make 210hp-220hp stock, some made 250hp, with a decent build(higher compression, cams, aluminum heads, 650+ 4 barrel, headers) they make around 300hp.
Regardless, I think it will beat the Supra in a 1/4 mile.. 351 probably has more torque, Supra could weigh anywhere from 3450-3750 without a driver depending on the model, could have any gears, tires.. and most important.. the driver.