Gauging interest on an American made 4340 4.00" stroke small block crank.
It would most likely be internally balanced, a 2.100 Rod journal and in the neighborhood of a $1000-$1200 price range. Let me know your thoughts. Thanks!

 

That sounds great and reasonably priced for a quality crank. Would custom pistons be necessary or would any existing off the shelf piston and sbc rod work?

 

With a 6.125 rod there are a host of 4.125 bore off the shelf pistons available from manufacturers like JE, SRP, and Mahle to name a few. Lots of choices.

 

Looks like BBO heads or even better Edelbrock or Procomps without would provide 10 to 1+ compression with a 10cc dish piston. No more milling new aluminum heads to get decent compression on a SBO.

 

10:1 compression aluminum headed 428 cid engine would be awesome.

 

2.5" mains or?

 

I would hope so since spacers in the DX block has been proven to be reliable for big power. Plus less friction with the smaller mains.

 

x2 I'd be interested.

 

Hey cutlass I thought bout stroking mine thought it wouldn't be worth it for my turbo build I'm already 4.125 bore

 

There's no replacement for displacement, even with a turbo.
Yes 2.500" mains.

 

I'm definitely interested in this. Any ideas about time frame?

 

We're looking for an existing forging that we can modify to work with the Olds bore centers and bearing placement. For right now it's moving forward. But if we can't find something existing then it'll be a dead issue. Raw forgings are just too much money.

 

Mark, what compression height is needed for a 4" stroke? I know it depends on rod length. I want to use my current 403 stroker pistons set up for a 6" rod and 3.5" stroke. I come up with a 1.58" current compression height. Looks like with a 5.7 rod would put them .050" in the hole. I would deck .020-.030" and run the Cometic .027" head gasket. I like the sound of 484 ci over 424 ci any day. Count me in and would come up with a deposit if I had to after I pay for the rest of that custom cam. I will be $500 a month richer come January.

 

Hold your horses Christian!😀
I wish we were that close but we're not, probably 6 months minimum, and that's if everything goes to plan.
You'll need to vase your compression height off the rods as mentioned. But be careful about using a shorter Rod just to be able to use your pistons. The shorter the rod the harder it is on cyl walls, especially on a 403.

 

Good point Mark on the cylinder walls but may risk it. At the same time 484 ci would mean huge torque. I wonder how long a stock TH350 and a 7.5" with a girdle cover and better spider gears would last? 6 months is no problem, this would be a track only car, my 88 CSC, striping the interior etc. Procomp heads would be needed, big valve #6 heads would be a no go, choke it to death. My current 3.5" stroked 330 crank needs balanced and would go in the 350 block eventually.