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forged 347.... or 402?? confused!!

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Old Jun 13, 2006 | 02:40 AM
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Default forged 347.... or 402?? confused!!

blew up the motor few weeks ago. i need to decide on a motor within the next few days! im at a complete loss! trying to get out of the as "budget friendly" as possible!!

i was set on a forged 347 but now im thinking 402.

my goal... high compression motor, would like to be around 500rwhp N/A. looking to do a big head/cam setup then add 200 shot.

my question is... will the 347 be all i need? i dont know if i can justify the price of the 402 over the $2700 price tag on the 347.

somebody help!! any info would be greatly appreciated!!
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Old Jun 13, 2006 | 03:05 AM
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If you go cheap you get cheap. My advice save,save,save and go with an Iron 408 forged internals with a set of hand ported Ls6 heads and you can spray the **** out of it.I did a set of ls6 heads for a customer forgot what cam he had but the car made well over 500 horse power NA and still had some spray.On the bottle 650 plus, is just how bad you want it buddy.
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Old Jun 13, 2006 | 06:11 AM
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This is exactly what I've been debating over the past week or so. I'm almost ready to just say screw it, sell the car, and buy a bike.
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Old Jun 13, 2006 | 07:21 AM
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Default forged 347.... or 402?? confused!!

If you are going to spray a 200 shot, then you definately need a forged bottom end. A 402 would not be an advantage over a stock short block unless it has forged rods and good pistons. Whatever size engine you buy, you need strong parts in it to handle the NOS.
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Old Jun 13, 2006 | 07:38 AM
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Look at what you can afford! 500+ a 200 nitrous shot is nice, but your gonna need further drivetrain mods, especially in a C5 to support that.
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Old Jun 13, 2006 | 07:59 AM
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There is no substitute for extra inches.............in any hole
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Old Jun 13, 2006 | 08:05 AM
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Originally Posted by Mike@TEA
There is no substitute for extra inches.............in any hole
Classy!!!
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Old Jun 13, 2006 | 08:07 AM
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Originally Posted by Mike@TEA
There is no substitute for extra inches.............in any hole
lol very nice.
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Old Jun 13, 2006 | 10:39 AM
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thanks guys for all the replys! i guess its just this is a one time thing. i dont want to make the wrong choice.

i blew up the stock motor on the spray, so spray still makes me a little nervous considering! the more i think about going with the forged 402, the less i think about using the spray.

driving around N/A with over 500rwhp isnt bad at all. chances are i would probably only spray 100 shot on top of that.

the 347 will drop right in, and the rest of the motor will bolt right up. is there anything different with the 402?

also... what would be the benefit of going with the iron block??
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Old Jun 13, 2006 | 11:03 AM
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if youre not going to spray much then why not go with an ls2 402 so you dont get the added weight of the iron and it would be able to handle a 100 shot easily
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Old Jun 13, 2006 | 01:51 PM
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If you want to spray a lot, I'd go with an iron block 408. However, with a 200 shot I'm sure a forged 402 would be fine. I've seen posts in here with 402s being sprayed with 300 shots with no problem. However, the cheaper route would be to build a 408 yourself. You can do it slowly and use the stock heads/cam/intake and upgrade as you go on. That's what I would do. If you go with a 346 you'll always wonder "what if?"
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Old Jun 14, 2006 | 06:43 PM
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I'm a good friend of Brian's and I think he's pretty much set on a 408 Iron block motor with something like a Trex cam.

Car will have absoulte speed stage 2 heads. The car has a LG's, Ram HD clutch, M12 Z06 trans, Z06 SP3.42 diff, DTE brace and will have a hardened output shaft.. Car will continue to run an LS6 intake with a ported TB.

He wants to make the most power he can N/A and then spray a nasty shot on top of it.

Still trying to figure if the TRex would be the best choice. The car is a daily driver, but we don't like them ***** setups... lol. It still needs to be drivable though.

Steve
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Old Jun 14, 2006 | 07:19 PM
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Originally Posted by King James
This is exactly what I've been debating over the past week or so. I'm almost ready to just say screw it, sell the car, and buy a bike.
ahaha i got the bug for that as well.... very expensive hobbies... then you get hooked on trackdays and mods mods mods..... and the rest of your $$$ goes to hell....
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Old Jun 14, 2006 | 09:43 PM
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I dont think anyones ever split an lsx block in half. Do you really need iron if teh aluminum holds fine?
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Old Jun 14, 2006 | 11:45 PM
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If I was going to go N/A or a small shot then I'd go 402 but if your going to spray very much then I'd go 408.
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