I've ran them on street cars with 426W and 440 short blocks with the M.W. top end with the 1964 750 CFM Carter carbs
If you get the right cam installed correctly they perform very well
The bigger the C.I you make the more power you will make with that top end
My first M.W. car I bought and ran had a smaller than stock cam in it due to the owner letting some one else talk him into a new cam when they were freshening the motor after he had spun a rod bearing in it with the stock air sucking swinging stock oil pickup and stock oil pan.
I replaced that oil pan and pick up with a 1966 to 1969 street Hemi pan and oil pickup and added the windage tray, work good, lasted a LONG TIME
They will outrun most stock street hemi cars without much effort
Good cars