I have been following this thread w/ interest since this is where I am in my build, and thought maybe I would gain some insight as to what crank to use...that is before the cat fight started.
From what I have read, Ford cast cranks and Scat cast steel cranks are both made from
crankshaft grade nodular iron using a similar process. The Scat being steel in name only, and in fact cast
steel is an inferior product vs cast
iron for crankshaft use. The steel only likes being forged. Ford had the patent, formula or whatever on using nodular iron. The bow tie folks did not want to pay Ford for using this technology, so they used a malleable iron that had to be heat treated, was still inferior to the nodular, and probably a big reason why forged cranks are more mass produced by chebby, perhaps answering your question as to why forged cranks are more common in chebbies. Chebbys answer to providing a stronger crank was to go forged...when they wanted a stronger rear, they use a Ford 9", and when they want a stronger transmission, they use an adapter to mate a Ford Toploader
. Guess they could not figure out how to use a Ford crank.
From what I have been told by several old time FE racers was that even a FE
cast crank is darn near indestructable, as long as they are properly balanced, get plenty of
oil, and the rods/rod bolts do not break. Most documentation lists 500-600hp as the max for a typical cast crank, but there are quite a few running FE cast cranks, 428s included, that are running in the 700-800hp range, and are spun to 8500rpm w/o failure.
From what I have experienced on my first Cobra build, it started as an iron block 427 w/ forged steel modified 391 crank. On one of my rebuilds (4 in about 3500 miles of use), I swapped out the steel crank for a cast crank (at least 10lbs lighter) and the steel flywheel for an aluminum one. The improvement was unbelievable with just the lightening of the rotating mass. As a matter of fact, I have a cross drilled steel crank (74lbs), a smoothed cast crank (64lbs), a modified 391 steel crank (having it knife edged/lightened, unsure of final weight), and a 427 cast crank with the grooved mains (66lbs). All .010/.010, all 3.78 stroke. I am still trying to gather useful info so as which one to chose.
So to answer your question, as long as you stay with a naturally aspirated engine, and the fact that its tough to get a Cobra to really hook up, a properly set up cast crank should do just fine.
And as far as your question about the expense, especially if you are new to FEs, do not let the Ford guys fool you into thinking that FE stands for Ford/Edsel...it stands for F*(#!@& Enormous and/or F*(#!@& Expensive
.