I was viewing the fastest truck list and i saw that there were very fast times for mods done on these trucks. I dont see how you guys are getting these times with so little hp. Dont get me wrong i am not trying to start and argument, but i am a little confused on how my set up is not running these times.

I just put in a 408 stroker "lunati rotating assembly" in my truck "1/2 ton 2wd" with my old 5.3 heads that are ported and have 2" intake valves.(cam=.567/.572,224/230, 114lobe sep. 11.1 compression, holley intake, accel 48lb.injectors, 4.10gears, 2200 stall, hughes trany pkg., shorty headers-flowmasters, K&N intake tube, Ls1 edit, and a set of M/T DOT's.
I took my truck down to the track, and for one the track was a joke that night. For some reason nobuddy could hook. I ran a 13.6 at 101. I know i can improve my 60' by a lot, but that still doesnt explain why my mph is so low. Any of you guys have any idea's?

 

You should get more like a 4000 stall and some long tube headers. Then you'll be in business.

 

Your 5.3 heads are choking your power. I'd highly recomend getting at least LS1 heads w/ 2.055" intake and 1.60" exhaust valves. Those shorty headers aren't doing anything for you either. With that cam I would also recomend nothing less than a 3000 stall converter or get a tighter LS cam with more duration, that cam seems a bit mild to me for your shortblock. I'm in the process of building stroker also, I'm going with a 246/246 600/600 110LS cam. By the way, who did your tuning?

 

What are you guy's seeing as far as horsepower from those long tubes. I know it helps the cars out a lot, but from what i have heard it doesnt help the trucks very much. Also what are you guys seeing, performance wise on the converters.

I thought that the heads off of are trucks were the same as the ls1's, so long as you up grade the valves to the same ones and borehog the ports to match.

 

Long tubes are worth 20rwhp, 20rwtq. Shorties are lucky to see 5rwhp, and 5rwtq. It will make a big difference in letting that 408 breath. 3000-3200 stalls are worth 1/2 a second in the 1/4. But like CashDude said, a bigger one would make help you more. One of the best mods other than nitrous or FI.
As far as heads, the aluminum 6.0L heads are the way to go. Don't think they are the same as the LS1 heads.

 

My goal over all is to get my truck as fast as i can all motor then through on the juice. My ultimate goal is some where in the mid 11's. I also know computer tuning is a must. All i have changed in edit so far is timing, torque management, and shift points. I hope i can at least get my truck in the mid to high twelves all motor. Well see, i will keep you guys posted.

 

I just put on some AS&M headers and the power increase is DEFINITELY noticeable, throughout the whole rpm range.

Its actually amazing how much of a difference these headers made. The sound of my truck has even changed. Sounds more like a vette, or camaro

 

If they make 20/20 on a stock internal 5.3, just imagine what they would free up on your 408

 

Like everyone has said so far, long tubes are a definite plus, SPECIALLY on big cube motors. 5.3 heads are similair to LS1 heads but, each have their pro's and con's. 5.3 heads are great for raising your compression ratio on a 5.7 and get great HP numbers with matching cams. For stroker applications, LS6 or 6.0 heads are the way to go-much better flow=much better HP/TQ. If you have 11:1 CR w/5.3 heads, you must have really dished pistons because if you don't, your CR should be closer to 12:1 if not higher. With no fuel adjustments and only TQ management/ shift adjustments, your full potential hasn't been reached. Talk to BigTex and Parish8, they're pretty damn good w/LS1 edit. Also, speaking from experience, your heads may have been over ported thus hurting your set up.

 

Thanks, I ended up running almost a .05 copper gasket with the type of pistons i have. I did the math at one point and then checked it with lunati. I think i am definitely going to ended up getting a set of long tubes and a converter. I dont know if i should swap my cam to a larger one or not. I believe it means i will have to machine out my heads for bigger springs and i am not sure how much hp it will add for the price to replace my cam again.

Oh, my heads are only port matched and polished on the exost side. The intake is borehoged to matched the valves with no other porting on the intake side.