Quote: No they are not special. They are in the "can't give it away" category. Also, 413s equally built with a 440 will always have less torque as torque is primarily determined by cubic inches. But what to do with a good 413 block? This is why I developed my recipe for a 472 built on a 413 nearly free block. Use the stock rods and a 4.15" stroker crank. Bore the engine to fit standard bore cast 383 pistons, the type with compression height about 1.83 or lower. Put it together, it is going to have to be balanced, should be close though. Use any set of open chamber cast iron heads, the 452s are nice. Use a camshaft with about 230 degrees of intake duration, we are building a torque motor. Use your favorite 440 intake.
If you do it right with home porting on the heads using the templates, you should end up with an honest 400 hp and 550 lb-ft of torque (guess-top dyno). This engine will outpull a similarly built 440 up to say 4500 rpm. Compression ratio will be around 9.5:1, pump gas friendly.
Or you can sell the 413 for 11 cents a pound.
R.
yup, bore it .062 over and you get a 383 bore size of 4.250
or, you end up with a 426 wedge. now tell me that a 426 wedge is junk. drop in a stroker crank and you can make as many cubes as you want. good set of heads and you can make 600 hp if you wanted it to.
but sonic check the block first, make sure it'll take .060 over!
