Well I've been looking at doing a pretty major face lift on the motor and changing it into a 387 so I thought I'd see what some of you had to say about it. So far just to give you an idea of what I already have its a 355 with Brodix RaceRite heads (23 degree, 200 cc intake 67cc combustion chambers), Victor Jr. single plane intake, Holley 650cfm carb, some huge Lunati hydraulic cam thats going to be gone with the build up,and forged rods and pistons making around 10.5:1cr (speed pro pistons, I forget what the rods are). I was looking at the Scat cast 383 crankshafts. Just wondering what everyone thought of these crankshafts. I was looking at building it up to atleast (key word ATLEAST) 500 fwhp and was wondering if these would hold it just fine or if I needed to step up to something like an Eagle forged crank setup. Also when I do the swap I plan on changing pistons and rods and bumping the cr up to somewhere around 11.5-12:1 but also cams/carbs as well so any suggestions on which cams would do best with the setup after its a 387 to produce anywhere from 500-600 fwhp would be great. By the way its not a street car even though I do plan on keeping it "street legal" for the class I race it in. Thanks in advance!

 

If you are looking towards building it for more than 500 fwhp, I'd step up to a forged crank. I ran a 383 with a similar build (11:1 comp, canfield 195 cc heads, crane solid cam, vic jr intake and 750 carb) for 3 years with a cast Eagle crank and SIR-rods, but saw one come apart after 3 years on a car making about 550-575 fwhp that was raced a majority of the time, but also was in a car that used a two-step. A two-step is hard on the crank IMHO, and after seeing the destruction and researching the cost difference, my new block has forged Eagle internals rated to 1,000 hp. I think better safe than sorry, especially if you plan on pushing the limits on a regular basis. If it was a street car not raced as much I might lean the other way, but the intended use is what sways my opinion.

Just my $.02

Derek

 

I agree with the above post, for the power level and useage that you're shooting for you need a forged crank. I'm using a scat 9000 cast crank in my 383, but it will see mostly street duty and produce a little under 500fwhp. For the hp and compression you're shooting for, I'd look into a nasty solid roller cam to match the flow capabilities of your heads/intake. Call some of the cam manufacturers with your specs and they'll recommend you a grind best suited for your motor.

 

The Eagle 4340 cranks are cheap to the point where it's hard to pass them up. Mine is a nice piece for the $ and balanced out very nicely with my Speedpro forged pistons and I beams. Building the motor as we speak. $485 from CNC Motorsports

 

i wouldnt recommend anything 4340 for power levels under 600hp. Ive built a budget 355 motor on $3500 that made 515hp reusing only the 4 bolt main-block, Forged steel crank, and rods that i polished the mold seems out to strengthen them or you can buy 5140 steel rods from SCAT worth every penny,and a roller cam with .540'' lift on it, with 11.3:1 compression forged pistons and an aluminum head its runs on pump gas 93 oct. To this day it still is running strong breaking the tires loose at 35mph with 3.42s in the rear of a monte carlo with a 4 speed muncie m-21

 

I have a 383 with the SCAT crank that is my dd. I havent dyno'd it yet, but it is somewhere around 480 crank HP. I would say go for the 4340 piece, or a 5140 forged piece for lighter weight. If you get the scat balanced, and use a good balancer, with good rods etc. it should do just fine if the more expensive piece doesnt fit your budget.

 

I make 589hp with my cast Eagle crank. Crower 4340 rods, SRP Forged pistons. M2 CNC'd Iron Eagle Platinum 230cc heads. 254/257@.050 with .712 lift cam. 9.5 compression and 91 octane.