Is it better off to get a new scat 9000 crank for 180 shipped or reuse stock crank? Shop said a good polish will take care of the stock one. Its from an 89 350 TPI. Plans are 355 Main studs, 2 bolt, we have Lunati Pro Mod rods (sweet deal), wiseco pistons 8:8:1 comp for now. Will be putting on 9psi procharger. Not racing it. Will be show car and maybe once or twice to the track. Will be professionally internally balanced and put together

 

if you're going to run a power adder i'd get a forged crank. i've heard lot of bad things about scat and for that reason wouldn't run one. if you're wanting to spend 180 dollars get the stock crank round and straight and the block preped for it.

 

If your stock crank will polish,I'd stick with it.No sense paying $180 for a new crank that won't really be any better than the one you already have.
In my opinion,ede is correct.You really should invest in a forged crank.I'm all about a budget,but with wht your already planning to spend,why not finish it off with a good crank,and your lower end will be bulletproof.

 

Its because were sticking with stock heads, stock TPI and stock eveything else. Only real add on is the blower. I figure myabe 325 at the wheels with the boost and it wont be revv'ed over 5K

 

Be careful with scat cranks. Scat has been cranking them out with a rough thrust bearing surface. Then the excessively hardened the crank. This makes the crank a file. It then chews the thrust bearing up and causes .015- .020 additional thrust clearance on the crank within 100 miles. . The metal is sent thru your motor and pollutes the bearings. Ask me how I know. Saw it happen to 2 ford motors, and 2 small block chevy motors this summer.

 

If you are not bumping up the cubes stay with the stock if it doesn't need to be turned down. And I have used the scat 9000 crank with great results put a 275 hp nitrous kit on it . and it worked great car went 9.70s at 140mph also drove it on the street. Maybe i'm just lucky wish my luck would help me win the lottery.

 

Anybody see stock GM cranks break? I did a few searches and found VERY little. All I see breaking is rods and melting pistons.

 

I have had three motors with stock cranks.The fastest one went 10.20 on a 225hp nos kit with eagle sir rods. The other two with stock x rods and arp bolts did well also. one went 10.8 on a 180HP non the other 11.10s on a 180 kit. All motors were budget built and street driven on pump gas.And not one of them ever broke a crank or rod.Cheap head gaskets and pistons are another story.

 

I need to post pictures of mine from my 355. It is the late 1 piece seal style. Snapped at the rear flange where the flexplat bolts on. The only thing holding the crank and flywheel onto the engine was the seal. I work with a guy that has broken the crank on THREE GM GOODwrench 350 engines, under warrenty. 3yr/50,000 miles

 

All of my motors were also balanced don't know if that makes much of a difference but it has worked well for me.

 

I had a stock cast crank 2 bolt bottom end (balanced and assembled meticulously) go 10.03 @ 134 on spray. Only sprayed it a few times but the motor itself made 465 hp and ran for 7 years ( in a stick car that was pounded on) and still ran strong when it was sold. I would have no reservations about the stock cast over a scat anyday. If your funds can support it go forged but I wouldn't be too worried about your cast crank IF you prep and assemble it properly.