CC306 vs. GM 847
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From: St. Peters, MO
CC306 vs. GM 847 Okay after some searching these are the two cams I am between. I want the 847 cuz it's way cheaper and still billet plus it's a little bigger. The heads I am using are LT4 heads with some bowl work and comp dual coils I believe which are good up to .600" lift. Which cam is better with full bolt ons I have planned. I really like the lope of the CC306 that I just put in my buddies 97Z. Anyone have the 847? What does it sound like? Which one makes more hp and tq? Also where am I gonna have to shift at? I am not too sure about the rpm range of these cams. Any advice is appreciated. 
Save yourself some frustration and have your heads flowed, and pick a cam that best suites your heads. Picking a cam based primarily on sound somehow seems incomprehensible to me. There are a boatload of cams available out there.
On The Tree
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From: Portage, MI
I'm glad you posted this, cuz my buddy and I are having this discussion right now too. I already have a 383 LT1, with a 224/230 112lsa, ported heads, and its just to small. I would say the GM, being bigger, would be the way to go, because of its lift possiblitys with 1.6 rockers, and the extra 4 degree on the intake. this will raise your peak power to about 6500-7000. I'd say the 306 is pushing 6500 though too. Both are going to make great power, and are very streetable with the right tuneing. I'm leaning towards the GM 847, just cuz, it's bigger....
and my 383's torque will help it be even more streetable. Good luck, oh and where can I get a GM 847? Gm direct? Let me know
and my 383's torque will help it be even more streetable. Good luck, oh and where can I get a GM 847? Gm direct? Let me know Heard a few sound clips of the 847 and it sounds better than the 306 IMHO.. I put it in my latest rebuild.. hoping it'll do pretty welll.. Go with the 847.. I do hear it kill's flower's on the side of the road though!
Damn.. But if the motor is apart and you looking for the best! cam. foryour app.. Get a custom grind.. They go for typically 300-350 or so.. But you'll get better result's from a custom one then a cookie cutter cam such as the 306/847.. But you can't beat the price.. sorry for the post whorin'.. You'll be happy either way..
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From: St. Peters, MO
Heck yeah that's what I was thinking....209 bucks....847 for me. At this point I can't afford to pull the heads to get some more flow work done....too much $$$$....but yeah that would be optimal. Does everyone think it's okay to spin the motor to 6500-6700 on the stock lower end? Any precautions I can take while the motor sits there in the car?
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Originally Posted by 93turboLT1
I'm glad you posted this, cuz my buddy and I are having this discussion right now too. I already have a 383 LT1, with a 224/230 112lsa, ported heads, and its just to small. I would say the GM, being bigger, would be the way to go, because of its lift possiblitys with 1.6 rockers, and the extra 4 degree on the intake. this will raise your peak power to about 6500-7000. I'd say the 306 is pushing 6500 though too. Both are going to make great power, and are very streetable with the right tuneing. I'm leaning towards the GM 847, just cuz, it's bigger.... and my 383's torque will help it be even more streetable. Good luck, oh and where can I get a GM 847? Gm direct? Let me know
and my 383's torque will help it be even more streetable. Good luck, oh and where can I get a GM 847? Gm direct? Let me know
Originally Posted by Jordan57
Heck yeah that's what I was thinking....209 bucks....847 for me. At this point I can't afford to pull the heads to get some more flow work done....too much $$$$....but yeah that would be optimal. Does everyone think it's okay to spin the motor to 6500-6700 on the stock lower end? Any precautions I can take while the motor sits there in the car?
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From: NYC metro area
Originally Posted by The LT1 That Could
what are the specs on the GM 847??......i must have missed it totally....never heard of it.....i was about to get a CC306, but glad i saw this!
You can buy the 847 here, from GMpartsdirect.com. It's part number 12370847.
My Bolt on 150K mile motor has seen numerous 6500+Rpms.. Why.. I dunno forget to shift or what not.. But i will say it died a very violent death.. 4 rod's 4 piston's, crank,block and numerous other failure's.. I think a rod bolt let go! oh well.. Anyway.. I think a stock ltx bottom end will be able to withstand 6300+ or so.. Albeit it's not going to be sitting at 6300+ for more than say 3-5 second or so.. You shift and start over again... If it's going to go.. It's going to go.. I have heard of numerious car's spin a bearing after a cam install.. SO tread lightly.. I myself had a basic rebuild put together w/ a block i had in the garage, new crank, rods, piston's.. added a 847 and some spring's on the stock heads to support the lift of the 847.. total was 2200 bux out the door.. i do the removal and install myself.. This motor is just a "hold" me over till my 396 has a set of heads ... So the spec's are posted up above.. are for a 1.5 Rocker.. the spec's for a 1.6RR are quite a bit bigger w/ the exh topping out at .598 or somewhere close to that.. the use of the 847 will require a spring change.. i have heard that the crane spring kit will work w/ the cam and a 1.6 rocker.. And their are a few other option's as well which can be discussed at a later time..
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From: NYC metro area
Originally Posted by IllusionalTA
it died a very violent death.. 4 rod's 4 piston's, crank,block and numerous other failure's.. I think a rod bolt let go! oh well..
That's one dead motor. Thread Starter
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From: St. Peters, MO
Oil Pan....wow. That's amazing. Okay new revised plan. Arp rod bolts....fresh valvetrain all the way through. Bigger Oil Pump and pan and 6300. Just waiting till next summer when I'll have the money to drop in something nasty 