I am putting together an LT1 with modest goals 1.VERY quite valetrain 2. 325 rwhp 3.NO check eng lights 4.run with or beat STOCK Ls1 (co-worker) Formula. Right now my plan is stock lower end,LE1 "econo" heads/cam,52mm TB,160 tstat and a TRIFECTA tune.Since I plan on keeping STOCK exhaust is the TB a plus or a wash.Also ,with these goals and the desire to keep exhaust stock is the Le1 cam too much -could i achieve these goals with a stock LT4 (NOT the HOT) cam and the le1 heads. The car will be daily driver,maybe 1 trip to track a year,shift at or below 6000 rpm.

 

Stock exhaust? You realize that headers through a muffler generally makes for a very quiet setup.

You could easily do 325rwhp with just a cam anyways..

 

I am aware that headers through a stock exhaust would be quite enough ,I am trying to avoid LEAKS and the little stuff that comes with "HOT ROD" mods-I am getting too old to track down header leaks or spend 4hrs wrenching to get that last 7 rwhp out of it!LOL 325-350 rwhp will keep me ahead of most ricers and beat my bosses ls1-so which cam?

 

Ai 185cc heads with matching cam for your application should get you there. Stock TB will be fine.

 

I will comment on each numbered question:
1. If you require very quiet valvetrain the do not use roller rockers, stick with stock rockers. They will faintly tick on tiny cams and will tick much louder on bigger cams with taller and faster ramps.

2. 325RWHP not gonna happen on stock LT1/LT4 cam, these two cams are nearly the same. Very possible with LT4 "hot cam" or LE1 cam and a rethinking of you exhaust configuration.

3. Do it "right" and you will have no SES lights. Attention to detail is key.

4. Not going to run with an LS1 without a bigger cam and headers, ported heads are not enough. Stock TB is plenty.

I think it is waste of time money to port stock heads and not get at least the LT4 hot cam. Also what is the point of porting heads if your going to bottleneck your CFM with manifolds.


But you are going to have the manifolds and heads out for porting right?

There is no secret to ensuring headers do not leak. Just check the flanges for flatness and use locking fasteners like Stage 8 bolts and decent gaskets. Also headers are going to make ~20RWHP and take you much further than porting heads and using a tiny cam. I dont see even 290 RWHP in you future with your stated goals and forget about the LS1 whoopin.


Respectfully I think you are being needlessly conservative with your goals that are not worthy of your time and investment. If you do the LE1 eco- heads, LE1 cam and mid-length headers you will easily make 340-350 RWHP and beat the LS1. Your shift point will be no higher than 6.2K RPM. The LE1 is extremely daily driver friendly.