If you HAD to choose??

The Kansan

New member
Aug 30, 2013
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Topeka, KS
Im curious if you HAD to choose between an Alternate fire cam or New stock gm crank in an engine build which one would it be. I know some people are going to say BOTH, but i want to know what you'd do if you HAD to choose between the two.
 

Harbin_22

Active member
Dec 4, 2010
3,858
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Southern Indiana
I had a brand new GM LB7 crank that lasted 5k miles with a stock cam and broke. I've got an AF cam with a 80k LBZ crank that has around 15k miles on this build with more power and abuse than the LB7 saw.
 

2004LB7

Well-known member
Dec 15, 2010
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Norcal
Is your crank broke now? If so then obviously the crank. If not then neither until you have saved up enough until you can buy both. Doesn't seem to help much putting an AF cam on a used crank

My 2¢
 

TheDirty06

New member
Sep 28, 2014
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Horton, KS
I went with an af cam and a new lml crank. You can find them at a pretty reasonable price. I wouldn't skimp out but to answer the question I'd say crank.
 

TheBac

Why do I keep doing this?
Staff member
Apr 19, 2008
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Moved to Engine Building, same as your previous thread.

I would choose the crank.
 

The Kansan

New member
Aug 30, 2013
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Topeka, KS
Is your crank broke now? If so then obviously the crank. If not then neither until you have saved up enough until you can buy both. Doesn't seem to help much putting an AF cam on a used crank

My 2¢

Its not whether i can afford them both or not bc i have a new lb7 crank and a wagler af cam on the way. For some reason the new lml crank i had would not fit in the lb7 block i have and would have to have quite a bit of material taken off to clear. I was just curious what people would choose if they HAD to choose one.
 

malibu795

misspeelleerr
Apr 28, 2007
8,235
550
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in the buckeye state
Guess you're looking at 1000+ hp build?
Crankshaft..
I'd be looking at Callie's 4340 or 4330 crankshaft or banks big journal crank/rod setup if available to public

I haven't been on the up n up with big builds.. last I knew AF camshaft is not sure bet..
Changing a firing pattern in a used crankshaft sounds like trouble
 
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The Kansan

New member
Aug 30, 2013
179
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0
Topeka, KS
Guess you're looking at 1000+ hp build?
Crankshaft..
I'd be looking at Callie's 4340 crankshaft or banks big journal crank/rod setup if available to public

I haven't been on the up n up with big builds.. last I knew AF camshaft is not sure bet..
Changing a firing pattern in a used crankshaft sounds like trouble

I know that a callies crank is out of my budget. AF cam i know is not sure thing but with a new crank it can hopefully only help. HP numbers i really dont have a goal just want a solid good running truck.
 

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
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MASS
Neither one. Find a good builder, keep the torque out down low and you won't have to worry.

Since when does torque down low break crankshafts? Mine broke cruising down the highway under basically no load at all and no boost. It is harmonics.
 

DMAXchris

It’s only temporary!
Apr 28, 2009
2,273
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Natrona Heights PA
Since when does torque down low break crankshafts? Mine broke cruising down the highway under basically no load at all and no boost. It is harmonics.

You have a Vvt & I bet it was broke way before that. 60k on my motor and 110k on my cousins motor. No AF cams. His LB7 crank came out of a 330,000 mile towing service truck, mine has 178k. Both big singles that don't make power until 3k. No oval bowl pistons either. I don't ride the hype train.
 

Harbin_22

Active member
Dec 4, 2010
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Southern Indiana
You have a Vvt & I bet it was broke way before that. 60k on my motor and 110k on my cousins motor. No AF cams. His LB7 crank came out of a 330,000 mile towing service truck, mine has 178k. Both big singles that don't make power until 3k. No oval bowl pistons either. I don't ride the hype train.

Haha the hype train and Oval bowls shouldn't be put together. I had 4 cracked delipped LB7 pistons after 5k miles of over 1000hp. Cast Ovals are well proven to stand big power. Mahle cast are proven to crack under 1000 over and over again.
 

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
You have a Vvt & I bet it was broke way before that. 60k on my motor and 110k on my cousins motor. No AF cams. His LB7 crank came out of a 330,000 mile towing service truck, mine has 178k. Both big singles that don't make power until 3k. No oval bowl pistons either. I don't ride the hype train.

Just because your two motors didn't break cranks doesn't mean there isn't an issue. If you drove drunk all the time but never crashed would you think DUIs were just hype?