I don't htink it's possible without every trick in the book being used and through a 4L80E it's going to be rough. That being said if it is done I bet it's with a huge cam which will require a giant stall (4000rpm+) to make the package work which isn't real practical on a big truck. IN a lightweight RCSB it would be workable though.

 

I doubt with a cam and bolt ons you could get 400rwhp. An 80e is going to suck up about 50hp according to 02Denali which has dyno numbers to baack up his claims. I bet with some lt's and all the other mods with a 230 with 114lsa I believe is what richard was telling me would shift the power curve waaay up in the rpm band but would produce more power with a little cheap port job through a 60e you could get 400rwhp. I let everyone know in about 2 months how much rwhp you can get from a 6L with stage 2 heads and a 224/228 110lsa cam and lts' with the normal other bolt ons through a transfer case. Then Ill put the juice on it and see what it'll do.

 

Stupidfast made 350/350 with a stock LQ4 running a 212/218 cam and bolt ons.

 

I know it is possible. I made 452 rwhp and 419 rwtq on a stock LQ9 with a custom grind comp 232/238 595/605 on a 112+2 this was through MAC midlengths and dual exhaust. Only major difference is I have a T56 tranny and a 12 bolt. Dyno was on 29" drag radials.

Later.

 

FirstGen - do you have a truck intake on there?

 

check it out.
http://forum.ls1truck.com/index.php?showtopic=4240

 

Truck intake, home ported TB, truck MAF descreened, open element cyclinder style K&N filter. 8.1L injectors.

 

I would agree. My 6.0 with an FMS 224/228 made 374 unlocked through a 4l60 and with a truck intake. With a bigger cam and locking the converter it should be no problem.