I currently have a 383 stroker and was doing some research on swapping the crank for one with a longer stroke. I found a company that sells 4340 forged cranks for $600. I am trying to decide between two cranks, the one that appears to be the more likely candidate has a stroke of 3.875". They do have one with a stroke of a full 4.000" and both have 350 mains. My question is would I have to swap out my connecting rods, which are I-beams, for H-beam type connecting rods? If I go with the shorter stroke can I stay with my I-beam stlye rods? I am hoping not to have to buy new rods to keep the total project price down. Any advice would be appreciated....

 

If you change the stoke here and dont change the rod length, wouldnt this be useless? I dont see any power increase there. I am no expert though. I would look for more opinions.

 

if you change the stroke,your going to have to change the pistons or the rods.you cant change the stroke and thats it.if you change nothing but the stroke,the pistons are going to slap the valves.you have to change the rods or the piston wrist pin location.just my opinion and i'm no professional

 

Yea, your pistons would either not be at TDC or it would be past it causing BIG problems. Good luck with this though

 

Yea, your pistons would either not be at TDC or it would be past it causing BIG problems. Good luck with this though and I hope your getting this done...

 

Sorry I should've given more details...

Yes I am planning on changing the pistons, as long as I don't have to pay for custom ones then I would definately swap out the connecting rods, as it would be cheaper. Now, I am also planning on possibly (at the track) running N2O again, so I'm thinking I am going to need to swap over to Hbeams, because I'm worried about the rods holding up. Now if I do need custom pistons, and change the rods instead to save $$$, do you think I should drop the extra cash on the Hbeams?

By the way The 3.875" stroke would give me 395 CID and the 4.000" stroke would be 408 CID.

 

The pistons will wind up with wrist pin holes across the ring lands, not a very good idea, especially if you are going to use power adders. Full floating wrist pins would be a good idea. You will need to clearance the pan rail at the bottom edge of the block as the bigger swing will cause the big end of the rods to hit it. The other problem you are going to run into, is the rods hitting the camshaft. You will need a camshaft with a smaller base circle and longer push rods to compensate.

The proper way to do this is to get a tall deck small block, such as the "GM Rocket Block", which comes with a taller deck, raised camshaft, and spread out pan rails. With this you can safely go to 455 CI.

http://www.sallee-chevrolet.com/Chev...are_Block.html

 

That's what I was afraid of, but I don't have the budget to do something like that right now. I guess I am going to have to be happy with a squirt of the funny stuff, every once and a while, for now. I haven't sprayed it since before I stroked her out last year and I was thikning maybe I should've installed beefier rods. Then I was like, well if I am going to go back and do that, then while I'm in there why don't I add some more cubes while I'm at it. You know how that goes getting more power leads to wanting even more power. I guess I am going to have to wait until the budget will allow me more breathing room, thanks for the advice....