Ive done a lot of searching, but still have questions.

In the summit catalog, it says the GM PM rods are 4340 forged steel, and handle 500HP. Isnt 4340 stronger than 5140 steel that eagle uses for the sir rods?

Im debating replacing the bolts with arp bolts, and having them resized. The machine shop quoted me $85 total, including bolts. They build a lot of race engines, so I trust them.

How would the stockers (with new bolts) compare in strength to eagles sir rods that are 5140 steel, and also rated at 500HP? And what year LT1s did the PM rods come in?

Im planning on the LE2/3 package, and maybe a little spray. Just enough to get to 10.99 since I have a vert and refuse to put a full cage in. So Im not too worried about the bottom end, but I do want reliability.

Im also using the stock crank, with main studs, and probably forged mahle pistons.

What rods should I use?

 

The PM rods are Powdered Metal, and they are well made from GM. They came in some 96 and 97 motors. PM is not 4340. The forged 5140 Eagles are a stronger base material.

Bret

 

http://www.automotiverebuilder.com/ar/ar99928.htm

This site says PM rods were in all LT1's by 95, but I personally do not know specifically.

 

My 95 has PM rods.

 

Our '94 did not have PM rods and one '95 that I built didn't either.

 

Measure the beam widths of the two rods, the eagle rods are quite a bit thicker.

 

The other problem with stock rods and n2o is they are pressed on and the stress wil cause the piston to stick on the pin and that is not good for parts. You would be better off going with a Scat full floater forged I-beam rod with 7/16" bolts for like $290 and have alot stronger piece. Later Clint

 

Those are exactly what I got for my new motor They are ALOT beefier than my stock rods were, plus bushed for full-floating wrist pins. Reasonable price too. I took them (along with the pistons and such) to the machine shop to get balanced, but when I get them back, I'll post some pics

 

Yes those Scats are some of the best bargains around, very nice rod for the price.

 

really? the same ones from flatlander.com? 2-ICR6000-7/16 for the 6 inch long ones? So bushed ones for full floating are better than pressed on pistons? Good info here so far!

 

Yeah I got the same ones, but 5.7" so mine are part # 2-ICR5700-7/16
I'm using a set of Probe industries forged flat-top -4cc pistons with them. I think it'll make a nice combo

 

I was in the same boat as you were about a year ago. The stock rods will most definitely be ok to run in your application but the stock rod bolts arent. That being said, do you buy new rod bolts, have them installed and pay to have the rods machined or do you just buy some Scat 5.7 rods that come with ARP rod bolts installed? I went with new SCAT rods because the difference in the price was only about 50 bucks or so. Also, the press fit rods/pistons will work just fine for what you are wanting to do.

 

What are the benifits if I go with a 6" rod, compared with a 5.7" if I do decide to go with some aftermarket I beams?

 

Don't skimp on the rods, I would get the scat I beams or H beams. You may as well get their 9000 series crank too, it's stronger than the stock crank but not as strong as a 4340 crank. You could possibly get a balanced and matched assembly from Scat, so call them.

 

there isnt too much to worry about for your application. a 5.7" rod will allow you to have a larger ring land which is great for boost and larger nitrous setups (200+) while a 6" rod supposedly gives more torque down low but i havent seen any proof thats worth more than a couple of horsepower. I would not get a set of H-beams unless you get a hell of a deal on them. I-Beams will work just fine but make sure you get good ARP rod bolts.

**thread hijack**-- what happened to your old block and heads?