Well i am rebuilding my 3.4 dohc and wanted a stronger set of rods for it but i wanted 3/8 bolts so i was going to buy some after market small journal rods but i saw 6 Child's & Albert 5.7 large journal rods my bodies had and he sold them to me for $100 and i was going to buy a crank from a uplander 3500 and have the rod journals turned down to 2.100 but now i am not going to due to I found these from Lunati they are bearings that allowed you to use the large journal rod on a small journal crank
http://www.lunatipower.com/Product.aspx?id=309

Well thats cool!

But... What most people do, is use the 60º bearings on the SJ rods, The rods need to be narrowed to fit the crank, and a new notch for the tangs needs to be cut for the 60º bearings. So I don't think you will want to narrow the bearings too. Something to think about.

Im still considering the 3500 Uplander crank, and if possible, the Eagle CRS570063D rods... They have the same journal diameter, 2.25" Sounds like a bulletproof combo. Still have to deal with the .927 diameter pin. But really, the stock components have been proven way over 400 HP. And several are just fine over 450.

ya I could have gone the sj rout but that wasn't insane i sold the rods back to the guy i bought them from and bought some 6.125 long rods and i will be buying the probe pistons I am trying to get a 3500 crank but the yard i called dint call me back. i will have the rod journals turned down to lj

quote [B]Originally posted by Fierobsessed:Still have to deal with the .927 diameter pin.

You can get around that by having bushings made that will press fit into the pin end. The inner diameter of the bushing should be the proper size for the pin you have, of course.

quote Originally posted by Fierobsessed: Im still considering the 3500 Uplander crank, and if possible, the Eagle CRS570063D rods... They have the same journal diameter, 2.25" Sounds like a bulletproof combo. Still have to deal with the .927 diameter pin. But really, the stock components have been proven way over 400 HP. And several are just fine over 450.

Keep in mind the surface speed on your bearings will be higher with the larger pin diameter. A trade off, since higher engine revolution speeds will stress the crank pin much more added cross section will help; but at the same time the surface speed and shearing force on the lubircant and bearings will be higher, which may inflate a already problematic rod oiling issue.

I have a question if i turn the 3500 rod journals down to large journal SBC will i loose the rolled radius due to .150 under sizing thats is .075 of material 2.250 down to 2.100

quote Originally posted by engine man: I have a question if i turn the 3500 rod journals down to large journal SBC will i loose the rolled radius due to .150 under sizing thats is .075 of material 2.250 down to 2.100

Yes and no depending on your machine shop. The shop I dealt with could not duplicate the factory subsurface radius but was able to do it in reverse so I have a 3500 radiused crank stroked to 3.43", but yes you will loose the stock radius, just have them radius the crank the conventional way. This will require you to use the 60 bearings to clear the radius or you can get sbc small journal bearings tapered to clear the radius.

Or taper them yourself.

[This message has been edited by Joseph Upson (edited 10-15-2011).]

This is all very interesting. I have a 3.4 i was going to use in my car and keep other stock so i could pass emissions. But the Damn digital egr for the ecm swap is illegal. So to hell with it i say! If i have to get fake smogs because i have a matter egr than stock then Im going to get my 200 bucks worth.

i would need narrowed large journal bearing due to i am going to turn it to large journal Joseph Upson i thought i saw that you changed the crank ring to a 7x am i dreaming or did you

quote Originally posted by engine man: i would need narrowed large journal bearing due to i am going to turn it to large journal Joseph Upson i thought i saw that you changed the crank ring to a 7x am i dreaming or did you

I changed it using a custom 7x ring I had made. CNCguy on the 60 degree forum may have some left of the batch he made.