no.. same exact price (318 or 360 stroker)... cept i can do bout 35 more inches.. so a bit more torque.. i plan to do a stroker if i find a 360roller block or this 318>390 if i don't.. just getting my car mobile at the moment.
18 cid 390 vs 408, probably about 20-22 lbs-ft but you could make more than some 408's.
Torque of different displacement doesn't matter much if geared in proportion. lbs-ft per cid is more important.
For a given hp at the tire at speed will have a fixed torque, so say eg.. 114 mph in 1/4 mile takes 300 hp at the 28" tire tq will be 1312 to the tire, so as long these car is putting down the same 300 hp to the wheel no matter /6 or 440 both are putting same torque to the ground.
Same goes for 20 30 80 97 etc.. mph.