SC ls1 or Iron 408?

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Dec 14, 2014 | 09:14 PM

GM MAN VINCE

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SC ls1 or Iron 408?

Im at a stand still with my build at the moment i thought i had it all figured out but another forum member brought this to my attention and ive been doing some serious thinking on it. I have this thread over on corvette forum as well the more opinions the better. I'm mainly wanting a setup I can run the **** out of and not have to worry to much.

These were the original plans for the car. 98 C5 6 speed
-Stock bottom end LS1 60k miles on current motor.
-A&A si trim
-Brian Tooley custom blower cam kit
-Comp turnin rocker arm upgrade
-New timing chain
-New oil pump
-New lifters
-ARP head studs
-LS9 head gaskets
-Alky meth injection
-Long tube headers
-Exhaust

OR

-408 long block from Texas Speed

The 408 is around $6800 for the long block only thing else i would need is a fast 102/92 and a 102/92 throttle body and maybe valve covers?

If i was to put the 408 in the car i would eventually run a 150 shot on it maybe more. Im not worried about the extra weight of the motor as im only worried about straight line performance. I like the idea of having a fully forged 408 thats brand new in the car that can hold up well to boost or juice. I would like 500RWHP out of the 408 NA.

Am i crazy for considering the 408 or should i just stick with my LS1 and run it till it pops?

Also this is not a daily driver or anything so down time means nothing to me.

Dec 15, 2014 | 08:03 AM

oscs

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Why don't you just build the LS1? You should be able to get a solid short block for $3500 or so.

Dec 15, 2014 | 09:19 AM

GM MAN VINCE

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I'm prolly going to run the stock short block supercharged and when it pops I'll upgrade to a forged 346.

When the stock block goes what normally gives first and what kinda damage? I no the #7 piston seems to be a weak link.

Dec 15, 2014 | 09:27 AM

oscs

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Quote:

Originally Posted by GM MAN VINCE

I'm prolly going to run the stock short block supercharged and when it pops I'll upgrade to a forged 346. When the stock block goes what normally gives first and what kinda damage? I no the #7 piston seems to be a weak link.

Many things can happen. Yea #7 is known to give trouble but a lot of people think that's becuase of heat. Look into rear steam vents being blocked off. Also I run slightly less timing on that cylinder as a precaution. IMO if you want to forge the 346 down the road you might as well do it now. Why risk damaging the block if that is the plan anyways.

Dec 15, 2014 | 10:34 AM

GM MAN VINCE

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I've never built a bottom end of a motor before is this something your average Joe can do?

Are the 98 blocks good to go seems like there's rummors of them being weaker than the rest?

I'm only shooting for 550-650rwhp

Dec 15, 2014 | 10:54 AM

oscs

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Quote:

Originally Posted by GM MAN VINCE

I've never built a bottom end of a motor before is this something your average Joe can do? Are the 98 blocks good to go seems like there's rummors of them being weaker than the rest? I'm only shooting for 550-650rwhp

I let a professional build my small block. As far as the 98's not holding up goes, I couldn't comment. However for a 550-650 build I couldn't imagine why a forged bottom end would have any trouble at that level.