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.
Torque is not about cubic inches as much as it is about stroke(hence stroker kit=more torque). In addition, the factory specs show the 65 413 with 340hp/470tq and the 413 x 2 4bbl as 390/485, The best 440 4bbl is 375/480 where as the hemi was 425/490. Even the 426 max wedge was 415/470 and 425/470 in the 13.5 to 1 comp.(ref Motors manual circa 1969). Therefore the 413 IS very competititive. We used to street race alot in the 80's and could find old New Yorkers with these motors in them that ran well. Blow one up, spend $50~100 and half a day swapping in a new one. Aftermarket parts availability is the limiting factor.
