I currently have a 99 z28 that currently needs the block to be replaced. My current setup is this:

ls6 intake
ls6 ported heads
224/228 .560/.570 115 LSA cam
Kooks LTs with catted ypipe
stock ls1 block

My original plan was to get a forged 346 ls1/ls6 block, but right now I haven't been happy with how loud my car is. To most people they like the obnoxious drone it puts out, it sounds cool. But to me will get irritating after a while, and I'm hesitant to step on it because how much louder it is than it used to be.

My question is, what kind of power would you expect I could get with a forged 402 block, with my above setup, except stock headers instead of the kooks? I know a lot of you are making like 480-500 hp with the 402 and a big cam, from doing some searches. My cam is about average. I would guess that im around 380-400 currently. What kind of power would you expect with all of the above except 402 block and stock headers?

Thanks

 

I personally don't think that cam would work too well with stock manifolds. If I were you, I'd just have a straight through muffler installed to tone down the noise, and get a quite catback, like an SLP dual / dual, or something.

 

you'll probably be somewhere near 470 rw, but teh power will come on very early. Putting stock manafolds on with that will really choke it up.. like stated about, change teh catback to somethign that is quieter, and leave the headers on the car, maybe even go with the stock catback, and get a cutout put in when you want to go to the track or just goof around.

 

So it sounds like I'll basically be screwing with my torque curve. Mid length headers could also be a possibility. I already have a corsa exhaust on right now which isn't that far from the slp dual dual

 

unless you don't have the header setup anymore, or have to take it off for emmissions testing or something, I'd leave them on, get some earplugs if need be

 

haha, its not really that bad. It's just me complaining . Since I had a plan to make a car for racing then I'll stick to it.

So if I went with the 402 and kept the kooks on there, I would be golden?

 

I'd say yes! they will be 100% a better choice then stock manafolds or shorty's... that I'm sure of.

 

That's a pretty small cam for that motor.

 

I think that even a high 230's duration will give you almost stock drivability. It seems that these motors should be closer to 113 on the LSA also.

 

Thanks for the info guys. That's what I was looking to hear. I will stick with my original plan and buy a 346 forged shortblock

 

You will be very happy with a 402,drove to the track yesterday with no slicks ,put my t-tops on ,aired my tires to 15 psi and ran an 11.83 spinning for 30 feet out of the hole let of throttle and missed my first shift over revved to 6999,ran a 11.83 at 118.5!then it rained .first time to the track in two years brand new everything !next week in the tens i hope,Have slicks now!