2000 Silverado 4.8 LR4 engine modifications
 

Hey everyone

Long time reader just joined finally.

I have a 2000 Silverado 4.8 4x4 manual Lr4 extended cab truck

My son and I have been collecting engine parts over time to rebuild this LR4 engine with some performance parts Bear in mind I'm learning the hard way in California being from Louisiana keeping things street legal so this is what I have so far. Where I'm stuck at now is the crank I'm not sure what stroke we want to go with though I'm pretty sure the piston bore we want to do.

Currently we have a camshaft 112/115 timing chain sprockets full kit set lifters rollers etc from Texas speed luckily I could have the item shipped to my dad's house in Louisiana and then mail to me because Texas speed does not ship to California
Trick flow 205 heads
Fast 102 intake manifold with 102 throttle & 92mm throttle not sure which one want to use based on stroke chosen and displacement.
Headers (will do a true dual exhaust when time comes)
Upgraded injectors and rail
Oil pump & water pump
My son and I are planning to do all the work except the machine Work of course 😁.

Now on to deciding the crank & pistons I am pretty sure we are going with the 3.81 or 3.82 bore. But the crank I'm stuck on 3.622 or 3.75. I really want to avoid maring the walls and any piston knock. I have a very reputable preformance machine shop I know to do the work so I feel confident there. But nervous about picking the wrong stroke etc and everyone's information is all over the place.

I do plan on redoing the exterior the upholstery hopefully putting the t56 transmission in it and holding on to it for many years to come taking care of it have it a little fun here and there but mostly just enjoy the pep of the drive. Coming out really like to pass it down to my son and whenever I am older.

Anywho any advice is so very welcomed and please keep in mind I'm the type of person where if I'm going to pull it out I'm going to replace the possible failure components when it's out so any recommendation is fully welcomed.

Thank you and God bless,
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Personally I feel like you're headed for a very expensive disappointment. You're likely to end up with something slower than what you started out with, at least at city street type speeds.

I think you should forget about the intake and TB. Jut pull it out, throw it in the trash, and get a LQ9 from the junkyard, and drop it in, as-is. Pay acoupla extra for a nice cherry one. Maybe put a VERY MILD cam in that; maybe one of the 212/218 crowd, something better than stock butt that the smog inspector won't notice. "Smog inspector won't notice" is the operative concept here. They don't check block & head casting numbers unless they suspect something. Best way to avoid that is to make it as visually inconspicuous as possible, and make sure all the things they'll be looking for, are right there where they're supposed to be. Make sure they don't suspect something and as long as it has all the parts and pieces bolted to it that it's supposed to have, and blows clean on the dyno (if they even still do that... they may just scan it nowadays), you'll avoid trouble. Injectors would be a possible need; the ones in the LQ9 are the same ones that were in 4.8s in the same years, and are basically maxed completely out. Any mods to a 6.0, and the stock ones are inadequate. Either the ones from a flex fuel engine, or a 8.1, are a drop-in; all you need from there is tuning. Which of course you'll need anyway no matter what.

Can't recall whether a 2000 still had EGR, butt if it does, then that's something you'll need to take into account when purchasing headers. Later engines didn't, which makes things less trouble.

Also not sure what the rules are for a transmission swap in a truck in CA. Definitely check on that before you do it. I do recall it was an issue in cars, when I lived out there. I left in 02 though so I could easily be out of date on such things.

Kostallo Registered User Last Activity: Mar 6, 2025 10:46 PM

He posted, came back one time the next day, and hasn't been back since.

Another one and done....