I am looking to buil a 383 stroker motor for my 86 IROC. I am looking at cranks. I am seeing some that are "interally balanced" or "externally balanced".
Can someone explain the pros and cons to me concerning the 2 different type of cranks?

I not looking to go radical with my old chevy, but I do wanna get more power & performance.
I do make trips to So.Cali (6 hour drive) to visit my daughter and love taking cruises along with the occassional street race or two.
The specs on my current engine is:

Size: 305 V-8 4bbl
Type: LG-4 vin# H
Mileage: 223,000
Fuel System: Carb.

I am going to keep my carb intake/delivery sytem due to smog, but I would greatly appreciate any info/help/tips from anyone here to help me out. This is my first go'round with this engine project stuff.

Thanks again, Big-Dogg

 

Internally balanced crank fits in a 2-piece rear main seal engine. Externally balanced fits in a 1-piece rear main seal engine. There are adaptors available to fit an internally balanced crank in a 1-piece rear main seal engine.

Ultimately, an internally balanced crank puts less stress on the crank.

 

Okay, Thank you for that info. Now, what kind of life expectancy can I expect from a externally balanced crank? ( I seen a good deal on one) What kinda performance? Are they road worthy (ie: long trips/high mileage etc? I'm asking cause I dont wanna have to rebuild again in the next year or two.
I drive my IROC like that performance muscle car it is. I have redone my complete suspension, & rebuilt the tranny (700-R4).
I put alot of miles on the car, and just wanna have power, confidence, & quality.

So any further info would be great!!

 

It's fine. Nothing wrong with an externally balanced crank.