Alright, have been doing research on MODS at this board for my NA 3800. A 20 HP boost (at the crank) will very satisfying to me. I plan to do following MODs:

1. FWI from Intense, I am not sure if the kit will fit in my 2000 regal LS with NA 3800?

2. Rockers, which kit you guys would recommend in terms of quality, performance gain and drivability?

3. Finally maybe a general PCM Tune from intense.

Will these stuffs give me additional 20 ponies?

Thanks.

yea id almost guaranty 20 out of that get the er rockers from zzp not the 1.9'* and while your in there port your lower intake manifold i think a lot of people would argue more gain out of that than rockers. and definitely retune for 2 reasons sure the extra power is nice and being able to run the 180 tstat but the shifts are soooo much better.

As long as you get 3.5" to 4" intake tubing, you should be good to go. The tubing is pretty flexible, but try to avoid having harsh bends. Your 2000 Regal should be the same under the hood as a Grand Prix, except for some things like the headlights and fender exterior design.

The world record for max wheel horsepower with an NA Series 2 3800 is 247, set by Wes Blair IIRC. And IIRC furthermore, he used 1.84 rockers. I believe those are the ER Rockers that ZZP sells, but I'm not too sure.

You are going to love the tune from Intense. Even better would be a custom tune, but the Intense one works wonders for your car. When you go to Intense'* PCM page and select your 2000 Regal LS, the only modification I think you should make would be to increase timing one or two degress. You're going to have to use premium fuel, though.

I'm sure you can beef up your car noticeably with these changes. Even if you don't get to 20 hp or if you breach the goal by some, any change is phenomenal when you get a performance oriented tune.

Thanks for the inputs. I don't want to push the limit. +20 HP is enough for me. One more question:
So the FWI intake is not necessary for a NA 3800? At least for my application. I should install a 180 T-stat, then the rocker and finally PCM tuning. Correct me if I am wrong.

The FWI is insanely necessary! The 180 is nice, but I don't think it'* all that important. You want to maximize airflow. The rockers will do that, but only because they will let valves stay open longer to get more air into the combustion chambers. The extra air that comes in, if it flows well enough, gives you the extra 20 hp.

You need to port and smooth the lower intake manifold (LIM) runners. An FWI is going to help air get to the throttle body, and the LIM will help the air move from the UIM to the head intake ports. A 180º thermostat helps the air that flows into the engine be more dense so you can get more oomph out of the air volume.

The rockers are great, and a PCM that lets the engine spin faster with more fuel being thrown in is even better for your car. The 180 thermostat lets these things work better, but you have to have these things first to notice something works better. I actually don't think the thermostat is all that important, but I have one anyway because it'* essentially free.

Overall, few people notice gains with a good thermostat. However, pretty much everyone feels a gain from a better intake. Get the intake first, port and smooth/polish the LIM, get rockers, and then a PCM. At the time of the PCM, throw in an extra $10 for a 180 stat because you're charged $20 to get a 195 thermostat tune. The 180 tune is standard, so you save $10 by buying the appropriate thermostat.

my opinion would be cai, tstat, and the tune first then rockers

I would agree about that. Also, if your going with a high lift rocker you will want to consider heavery springs.

and from what ive been reading i think porting your lower manifold is prolly before rockers too would you agree dan?

Everything works together. Your flow will go as fast as the most restrictive point will allow. I worked backwards, Exhaust, rockers, intake.