[Formulajones]

Originally Posted by Jay S

A forged rotating assembly will be closer to $2300-2600. I would not use an off shore cast crank with a 280 cfm round port unless it was a really mild build.

We have a couple 3.25” N cranks turned down for 3” engines. I kept with 2.25” journals. It was pretty economical, we used an Olds thrust bearing and a spacer cut with our plasma table. I had to turn the oil seal surface down on our lathe, the crank grinder didn’t have a narrow enough stone. I spent another $80 to grind the mains down over a standard crank job. Better than an off shore cast, weaker than an off shore forged. One of the guys up here does quite a few 3” engines like that. His personal car is about 600 hp plus an occasional 200 hp NOS hit. The strength of the N crank depends on how it is prepped, and the previous service life. A 455 2bbl has a different service life than coming from someone’s 20 years of abuse in a 600 hp bracket combo. It depends on what you can find.

I know of a 406 with 72 cc round port E heads with ram air manifolds and a full exhuast it made a little over 350 hp on a wheel dyno. It had a comp HR mutha thumper cam. That would be around 420-430 hp at the flywheel. Kind of a crappy cam pick with the RA manifolds imho, headers might have been worth another 30-40 hp with that cam. Wouldn’t have taken much to get that engine well into the 11s. Similar combo to a 400 with speedmasters. A well picked HR cam paired up with a great converter 11.50s would be pretty doable with the 400.

Yep, I built a 428 with a 400 block, stock 428 crank turned to 3 inch mains back about 22+ years ago when aftermarket stuff wasn't really flooding the market. Proper crank prep is the key. I ran that engine hard all those years and daily drove it. It's still in one piece and just fine.