yup

 

with a 408, you should be close to 550-600 @ the crank. Example, my motor is close to 600hp and others are trapping 120. TRanslate that into an ET and you get 11'z easy. That's on a N/A application 11.3 cr, 2.08/1.060 heads, 246/248 59x/6xx cam.

With a good set of heads, not necesarily AFR, you should be well into the consistent 11'z on an auto with a 3k+ converter. If your gonna do FI, make sure thats wat your gonna do and have some money saved up for the necesary OOPS that may come. The CR has to matched so you would need to have the FI kit ready to drop when the motor is ready. Or your gonna run a sluggish motor for a while.

IMO, get so race heads (APE has a set of 6.0 heads that flow great), matching valvetrain, a rearend and some STF, torque arm and DR'z. YOu should be fine and very happy with the outcome. Trust me, i doubted to but not anymore....

well, and if you want more, you can alwayts spray it confidently 200shot and hold on!!!

 

well i voted on turbo also but now i'll say heads if you're just wanting to go 11.5s.don't forget suspension also.

 

Maybe I left out my track is at 3600'. I was thinking of a smaller cam like in the 224 range 114 . Something with just a mild hint of a lope, and then make up the rest with turbo. I realy like the idea of a turbo. I sure like driving other turbo cars on good rode races. I am possitive I will get a good FI kit, and worry about AFR Heads latter.

 

If 11.5's is all you are aiming for, just get some nice heads and a custom matched cam. This should get you there no problem with a 408. Use your stock heads as cores and get a nice set of stage 3's from someone--------->
Get some 6L heads and you can do the mild 5 psi of boost from a turbo sometime down the road. This would set you up for 11.5s now and much quicker later when you get bored.

 

that fine, but remember you need to address the heads so you can maximize the air being forced into the engine. Without that and large cube motor, you'll hurt your times....

good luck. Turbo is great and very addictive!!! My old TSI AWD was close to 21psi before i got rid of it.....

 

I think all of you are right. I will work on the heads, getting some gathered up. But I am going to go ahead and get the FI Kit before I finish the engine or put it in the car. So I guess the verdict is to go with a ported set of heads, mild to moderate cam, and FI the car. I should be able to do what I want to with that set up.

As far as FI goes, I would love a turbo kit, but they sure do look like a massive pain to install compared to a supercharger kit. I am sure it is worth the trouble though.

 

I've got some good 6.0 heads if you're interested. I'm thinking about tossing my motor in the garbage and starting over. They have never been on the car as I've been waiting a million years for GM Parts Direct to ship my ****! If you want, I can post the flow numbers.

 

for your mild application, i would suggest a supercharger...ATI. Air intercooled and with 8-10psi on top of that 408, well, you'll be well over your mark!!

good luck, keep us posts............

 

What do you want for the heads?

 

I paid $2200 for them. Here's the flow numbers : https://ls1tech.com/forums/generation-iii-internal-engine/225742-what-should-done-these-heads.html
The bowls were not worked that much, so you could have them done to whatever you want to do. Also, the exhaust ports weren't flowed with a pipe, so the numbers look low. LMK if you're interested. I can take pics if interested.