Anyone every though about swapping a 4.8 for a 5.3 in the late model Silverados? I started to think about this today as I worked on my brakes.

Does anyone know what would be involved in doing this. Truck has a 5 speed with 3.42 gears. I believe the 5.3 backed by the 5 speed would be a blast to drive.

The 6.0 drops right in....

Thomas

hell the new LS7 would go in with a little bit of work.

If you are pretty serious about this try www.ls1tech.com in the conversions and hybrids section. There are some guys in there that know there stuff. With the right motor mounts the 5.3 should drop right in. The 5.3 is almost identical to an Ls1 btw.

4.8 & 5.3 are the same motor except for displacement.

I had a '98 5.7 w/3.42 gears, I now have a '05 4.8 w/3.23 gears and I can honestly say that the '05 pulls every bit as good as the '98 and gets 2-3mpg better fuel economy at least. What are they using for discs? pie pans? I made a trip to Colorado and have had the pulsating brake pedal ever since, came back the long way thru the curvy mountain roads.

Anyone every though about swapping a 4.8 for a 5.3 in the late model Silverados? I started to think about this today as I worked on my brakes.

Does anyone know what would be involved in doing this. Truck has a 5 speed with 3.42 gears. I believe the 5.3 backed by the 5 speed would be a blast to drive.

My truck is an 03. There is a 10 HP difference between the 408 and the 5.3. It's not worth the change, unless your engine is shot.

In the 99's there is a big differnece in the torque. I dont recall but exact numbers but it was around 75 to 100 ft lbs and they also made about 40 more horeses also.

After 99, the first year the ratings when up in the 4.8.

Any of the late model small blocks will physically bolt up and no one would be the wiser...not even the smog police. A 6.0 will look exactly the same as a 4.8. The difference in power between the 2 is so minute you probably wouldn't feel it. An edit program to un lock the PCM is a whole bunch cheaper than a new engine and will easily gain more power than a 4.8-5.3 swap.

A 6.0 will bolt right in, and would work fine. The Gen III platform is an excellent platfomr to build on. I am currently building a forged 348 for my'98 Z, running the stock crank, with a 3.905 bore. I am running the factory heads, with a very extensive port job, and a fairly large cam (24?duration/61?lift), and will be running a heavy dose of N2O. I'm shooting for 9's on the spray, and I am using quite a few factory parts.

You may talk to a chevy performance dealer, I remember hearing from a tech friend that the manual tranny won't hold up to the bigger torque motors. I don't think GM offers them w/ a manual, except for in the cars (Corvette ,Camaro)

I had an '00 with the 4.8 and traded it in for a '05 with the 5.3 and the difference in power is quite noticable. The '05 comes stock with electric fans, which might make a difference too. But as far as a swap, I don't know if I'd waste the time or money. Just trade her up!