lemans396

I've noticed that most 383 stroker kits that feature internal balance have 6.0 rods and kits with external balance have 5.7 rods. Can anyoneexplain why?

SPD DMN

I think it is just coincidence.

88-406

I'm with Vette92!

The 6" rod may be a little better suited for higher RPM operation. Either way, it'll make good power.

KM

MrJay

You dont have to use as much mallory when you internaly balance when you use a 6.0 rod, the more you can save on mallory the less it will cost you to have the engine balanced.

Jay

RACER7088

The six inch will balance easier due to the lighter pistons and longer counterweights.

5abivt

the 5.7 rod will actually flow more air in the lt1, which results in more power. usually the opoposite is the case. When using a 6.0 inch rod the rod keeps the piston at tdc longer, and at bdc longer, allowing more fill and more time for the mixture to burn, however, the time it takes moving from tdc to bdc is increases significantly (more piston speed) which can result in port stall (air cant move any faster), thats why most Lt1s actually lose power when built with 383s. Airflow research and GM both found the same thing, thats why LT1s come with 5.7 rods. =)

SPD DMN

:bs

That is the first I have ever heard of it being different for one specific engine, and I have never heard of anyone loosing power in a 383 because of using a 6" rod. The reason they used the 5.7" rod was because it will not cause as much wear as the 6" rod will. GM does not build them to get the most out of it, they build it so it does not come back to them. Pretty much the same reasoning LPE uses.

GlockLT4

:yesnod:

ColinOpseth

i thought pistons for the 6.0" rods were prohibitively expensive..

88-406

How much are pistons for the 5.7" rod?

km

J Z06

My friend had a Lingenfelter 383(Similar to mine) with a cast 400 crank, 5.7" Pink rods and a set of hypereutectic 11:1s. It was a monster! You should be fine with either rod. I opted for the Oliver billet 4340 5.85" though they're overkill(I only shift between 58-6000)..it never hurts.

good luck,and you're REALLY going to like the 383!!! :yesnod:

5abivt

i guess i kinda phrased it wrong. The 383 didnt lose power, the 5.7 will give it slightly more power, thats all.

SPD DMN

Good pistons will cost the same. The only real reason to choose a 5.7" rod over the 6" rod in a 383 is if you plan to shoot a lot of nitrous or are running a blower with quite a bit of boost. The 5.7" rod allows the piston to have a thicker top ring land whereas the 6" rod forces the rings to be higher on the piston.

I run 5.85" rods, but mine is a 396 (and I run Nitrous).