You can put together a 421 cub with no machine work just cut domes and you can do it all yourself. You don't even need to port them, they haul ass right out of the box, just put good bearings on a 4mil crank and have it welded.You can even run stock style cool heads with big bore domes 68mil. In my opinion get a duneable override and drop it all in and go. The money you will save on machine work will buy your trans and a lockup clutch.You start making alot of power with a banshee and they become hard to shift without a good trans. A duneable override is one of the best mods you can do. Alot of people run them and without one you would be at a hudge disadvantage. Just my 2 cents.