I have a 5.3 4dr 4wd 08 Silverado 1500 we built it with fully forged rods crank pistons whole 9 yards stock tbss 92mm throttle body k&n breather cam is a
228/232 @0.50 lobe lift .370/.353 valve lift at 1.7 is .629/.600
lsa 108 and intake center line is 105 has a 4.00 inch stroked crank pistons are stock bore 3.780 have valve reliefs bumped compression up to a 10.6 to 1 . stock 243 heads but does have the trunnion upgrade tsp recommend pac .660 duel springs titanium retainers long tube headers 3000 stall probably needs more not sure 4l60e trans stock for the moment &3.73 gears has 33x12.5x20 and has been tuned by a guy that is very well know and very reputation for tuning racing engines and dyno’s to Daily drivers and it just seems sluggish also has very slow throttle response forgot to mention also have nitrous kit is about to be installed to truck in the next couple weeks and going to get tuner to get truck on Dyno hopefully soon to get it like it should be. But is there any ideas to why it seems so slow below 60mph above that it’s got some pretty good acceleration up at least 130mph far as we have tried it so far just that 0-60 is a massive turd and very disappointed could it just simply be the tune or did I just get all wrong parts??? Tune setup for 93 octane and yes it was built properly already driven almost 500 miles oil psi 40+ at all times and strangely it doesn’t have much chop at all which is very weird considering the cam specs and all any thoughts other than it being a crew cab 4wd truck seen bigger and heavier with same or less hp way faster

 

If you made all those changes and are running the stock tune I would guess that's most likely the issue. I will add this, With that much money in build I wouldn't drive it until it was tuned. It would sure suck to hurt it with a bad tune and that's a real possibility.

 

Did you degree the cam? That parts list looks like it needed to be done.. What computer you using? GM?

 

K&N air filter plus a MAF = all kinds of trouble. Clean your MAF and get rid of the K&N. The oil from the K&N coats the MAF and doesn't allow it to report the correct amount of airflow into the engine. Another member on here had issues with this a couple of days ago: https://ls1tech.com/forums/pcm-diagn...s-fouling.html In my own personal experience, I had a mail order tune done years ago on a built LT1 in a '95 Caprice. It wouldn't even spin the tires at all after I got it running. Got the advice to clean the MAF and it felt like I'd added 50 HP to it. Instant power increase. Try it, it may just work for you.

 

3.73's with 33" tires is not the best in a heavy truck
3000 stall with that big of a cam might be a little tight

have you ran it at the track?

 

I would look hard at the tune and the stock TBSS throttle body is 87mm, not 92mm. I know, I own a 2008 TBSS. The converter is key and like already said, 3.73's w/ 33's is not optimal. I would have cammed that different, but you already have it running. I would degree and/or advance the cam and make it's where it's supposed to be. What brand of converter are you running? That makes a difference too, not all are created equal.

 

Get a cam spec’d for your build.

 

It has been tuned

 

[QUOTE=pdxmotorhead;20483309]Did you degree the cam? That parts list looks like it needed to be done.. What computer you using? GM?[/QUOTE

It was properly installed and yes us the original computer just has a hp tune out in it

 

Also has a brand new and maf and I have cleaned it once already just to make sure

 

have not run it at the track yet I have to get a new trans mission built first

 

did you ever figure out what was wrong?

 

Have you read the whole thread??

 

yes and he never says what ended up being the problem

 

After a year and a half, it's likely we won't hear it here...

 

He hasn't been here since a bit after he last posted.

 

I skimmed thru the thread and noticed the under square design.
I wonder what the cam grinder had to say, if they were even aware.
Guess we'll not know, at least this time around.