OK.....Time to look into this merging of parts. A couple of ?'s to confirm...... 425 crank is forged steel? 425 crank is the only one for T-400 application? What does a 425 crank weigh? What is the main journal size on a 425? Does the 425 crank take the same balancer as a 455? The wait for an aftermarket crank is 6 months and beyond,It's time to explore different avenue's. Thanks in advance!
425 The 425 crank IS forged steel. The rods are forged steel. rb. dia. 2.249-2.50 mb dia. 2.498-2.499 I think I remember the crank flange changing. Cant remember the year. But I once used a 1959 crank by modifying the flexplate by having a machine shop to cut out the center hole to match the flange on the crank. Did not change the balance of the eng. any. That th 400 really works good with a nailhead. Cant tell You about the balancers. Sorry. :laugh:
You have to put Bearings Spacer in the 455 Block to run the Nailhead Crank Main Caps and block. Or Have Caps Made still Have to Down Size Block Main Saddles Weigh not shure let me check have some 401 Nailhead Cranks. Kenne-Bell put a Nailhead Crank in A 455 Years ago. I don't remember the stroke on the 401 or the 425 Can some one help with the Stroke on both these engines
2.5" mains........Spacers & caps can be done. That's light,Stock stroke is 3.64 so with 2.25 rod journals you could go to 3.79 stroke and 2.100 journals or even 3.89 stroke and 2" rod journal and just like that you have light strong crank for a 455.
You could have it welded and have it reground and get a bigger stroke out of it. Tommy Ivo was having these done years ago Calif Crank Company did it. It's steel no big Deal to weld
The Dyno 2000 Numbers 4.350 bore at 3.790 stroke 450 inches 4.350 bore at 3.890 stroke 462 inches 4.360 bore at 3.790 stroke 453 inches 4.360 bore at 3.890 stroke 464 inches 4.375 bore at 3.790 stroke 456 inches 4.375 bore at 3.890 stroke 468 inches Nailhead 401-425 Same stock stroke
455 Balancer Here's some info I saved....from Steve B.: >> measured, fitted and compared the 455 BHJ balancer, a stock 401 balancer and a stock 455 balancer extensively. .210" off the back end of the 455 balancer, a balance, and away you go! The slot for the timing indicator is in the same place in relation to the keyway, and the weight is in the same relative position on the 455 and Nailhead. I will be using the BHJ balancer (SFI rated) from my 455 on my next 425<< I've read post from others which stated the 455 balancer will fit the 401/425...I think you are good to go!
1.880 Rod Journal Honda Pro Stock Stuff. You want some weight gone GETTER DONE !!!!!!!!!!!!!!!!!!!!!!!!!
The smaller mains on the new block are 2.75". I wonder if it's possible to go 2.5" instead? The 425 crank would open up some possibilitys! How hard are they to find? o No:
That's a good idea. I don't no if they would do it for the new Block Something to ask. You Have to Weld the Nailhead to get more Stroke.The Cranks on finding them Have 4 sitting in the Shop. I don't think there hard to Find i have Four
all 401 and 425 engines had steel cranks and forged rods. i have one crank in my shop and access to at least 5 more dirt cheap. Bob
I have the same question in mind.........W/O welding you would no get more than 3.89 stroke on a 2" rod journal,But this would be good for smaller CI combo's. Not to mention,You can always cut the block bigger if you want to go to an aftermarket crank at some point.
