OEM 340/360 rod in a 408 stroker...??

[dusterdoug]

Anyone doing this? I know there are many different H and I beams in the aftermarket, but curious is anyone has stockers in a low-budget 408/416...

If so, how are they holding up? Any block grinding required...??

Thanks
DD

 

[thanson_mopar]

yes, Im another inquiring mind that would like to know.

 

[70aarcuda]

are you building are race motor...or just cruising around town???

yes...the bottom of the bores will needed to be clearance for the rod bolts

 

[stroked 340]

I ran Eagle i-beams in my 416 until one of the rod bolts let loose at 8500 rpm's(yes i was not happy)..if you don't intend to make 500+ h.p. i'd go with a set of the Eagles you can buy them for what its going to cost to have a stock set redone,by the way i DID'NT need to notch the block for clearance..

 

[dusterdoug]

are you building are race motor...or just cruising around town???

yes...the bottom of the bores will needed to be clearance for the rod bolts

I ran Eagle i-beams in my 416 until one of the rod bolts let loose at 8500 rpm's(yes i was not happy)..if you don't intend to make 500+ h.p. i'd go with a set of the Eagles you can buy them for what its going to cost to have a stock set redone,by the way i DID'NT need to notch the block for clearance..

AAR - A street/strip deal. Puttin' around and 3-4 track outings a year, maybe. What are your rods of choice?

Stroked - The SIR's are priced right, but I've heard alot of horror stories about them. One in a 318 daily driver. Wait a minute, 8500 r's with a 4.00" crank?? YIKES!!

I have really, really good luck with LY rods over the years in 440's and I know from various other's that the OEM small block rod is pretty reliable, so I'm just wondering...

 

[moper]

I answered you on Moparts too...
The early 318 and all 340 rods are bushed already. To have a set redone properly cost me about $300. The same will be true for the later (after '71) 318s and all 360 rods need to have bushings installed to run most piston choices now. The only equivolent price rods are the SIRs. I'm not a big fan of SIR rods but if cost is the only concern they are around $280/set assuming they need no work. And some do. Any rod that has a rod bolt an nut, ratehr than a cap screw, will need the bores notched at the bottom. Some H-beams will need clearance regardless of the capscrews. Any build that wont be reved over 5800 and under 500hp will live just fine on factory rods. Above either of those, you should get better ones.

 

[70aarcuda]

scat 4340 I beam rods are about the same price as the eagle 5140 SIR rods...

 

[flyfish]

scat 4340 I beam rods are about the same price as the eagle 5140 SIR rods...

I agree, and that's why I have Scat I-beams in my motor.

 

[dusterdoug]

Yes, I was alerted to Scat's and a set are on the way for $299. Appreciate the input...

 

[340sFastback]

And the Scat i-beams require no notching of the bores. My local machine shop checked over my Scat rods and were impressed with what they saw. None of them needed any clean up. But you should still have them checked anyway.

 

[Guitar Jones]

I use stock factory rods in my 360 with W5 heads and run it to 7200-7500 regularly with just ARP bolts in it. Never had a problem.

 

[1wild&crazyguy]

$150 with arp bolts is what it costs around here to redo some 340 rods.

Stock floating pin 340 rods are good for a 500 hp 408 no problem, after 540hp it's a crap shoot, but depends on the build.
But really those rods are good for 8000rpm if done right.
I've turned mine 7000+ rpm many times.
A good friend of mine turned his 8000rpm even touching 9000rpm in circle track racing back in the day at el cajon speed way.

 

[1wild&crazyguy]

I bet you could put dinky 273/318 rods in you're average 450 hp 408 and it would live just fine...

 

[Guitar Jones]

Oh my old 340 saw 8000 RPM and 8500 in the water many many nights with the stock rods, polished beams, floating pins, weight matched with ARP bolts, never a problem there either.

I have a set of H beam Eagle rods laying around that I'll use for the stroker, mainly just because I have them, but I don't really think I'll need them at 600 +/- HP.