5.75 rods vs 6" rods in 350 Street Stock

[mharper2005]

I am building a 350 for the street stock class. I have heard different opinions on what size rod to use. I will be racing at a 3/8mi with tight corners. Some say the 5.75 make more torque and some say 6" make more torque and HP. I have noticed that almost everyone says that the 6" rod is easier on the cylinder walls and because theres not that much difference to go with the 6" anyway. Some say because the piston is lighter with the 6" rod itll spin faster thus making more torque and HP. Does anyone have any kind of dyno comparison on these two senarios?

[JustAddDirt]

I am no engine builder, but you will have higher piston speeds with the 5.75 rod. it will also make more torque with the 5.75 rods. motor will typically rev quicker with the 5.75

6" rods will be a little easier on cylinder walls but you should not notice a difference in a race engine.

I have 6" rods in my motor, but my engine guy was telling me the benefits of a 5.8" rod, not necessary a 5.75

[50j]

The piston speed would change with stroke. A longer rod will generally use a lighter piston.

[fastford]

you have a longer piston dwell with a longer rod, which means it stays at the top longer. this is better for higher rpm engines. in an chevy engine turning less than 7000 rpm , I prefer the 5.800 rod as well.

[hogracer3d]

5.94 GM powdered rod is an interesting deal, not very well known out of the 4.3l V8 baby LT-1 that was found in police and taxi's.
depending on what "street stocks" are nowadays some places they are 14 degree 740hp, and other places they are stock cast iron exhaust and a 2bbl

[Lizardracing]

I would think the longer dwell time at BDC would be advantageous to the smaller head/intake/carb engines. Assuming the right cam was chosen to start with.

[perfconn]

Don't know where you will get 5.750 rods or 5.800 unless you special order them made.The 5.700 & the 5.850 are normal like the 6.000 is.

[mike22l]

Here's the deal. 3 HP gain with a 6 inch rod on the dyno with a 4 hp reduction in torque. On a 3/8 mile track torque wins races. Go 5.7 for sure. I proved it on the dyno. 358 vortec head street stocks 2bbl 415 hp

[HINKSON AUTO]

I would prefer the 6.0 rod engine over the 5.7 rod engine. I like the 6.250 rods with the with a 3.48 or 3.5 stroke, The 5.7 and the 6.250 rod 2 barrel engine will peak at the same RPM but the long rod engine at 7500 RPM will make apppox. 30 horse over the short rod engine and will have a much flatter torque curve. Any 5.7 rod engine I have seen will fall like a rock after peak power. I use a lot of 6.125 rods in restricted classes again fatter torque and better power past peak power. Flatter torque curve wins every time.