Packy

iTrader: (11)

Alright, so my dad does a lot of towing and his 4.8 is shot and worn out in his 2003 Silverado 1500. So he found a nice low mileage(30k) 5.3L from a '06 model truck. Will everything swap over from his 4.8 to the 5.3 shortblock? He is going to put a cam in while doing this also since he has everything out. I was thinking of some heads as well. I was thinking of some old LS1 heads that I have with some 918 springs. Like I said he mainly just drives it daily and tows his camper and boat. Anyone have any other suggestions or pointers it would be greatly appreciated.

00K1500

iTrader: (1)

Yeah, straight swap from 4.8 to 5.3 stuff. All externals are identical.

viciousknid

iTrader: (8)

I believe that they changed to Gen IV in 05 so there are a few adjustments you will need to make. Not sure on all of them but I think the cam sensor and knock sensor are in different places and that the 06 may have a different cam gear or something. May research it on here or wait for someone to chime in that knows fact

budhayes3

iTrader: (19)

I was under the impression that the LS2 was the first to go GENIV, and next were the GMT900's...99-07 classic should all be GENIII

iamkeniff

iTrader: (16)

chevy/gmc stayed gen III until 2007 gmt900
that 06 will swap right over in your 03.

viciousknid

iTrader: (8)

Yep, that's correct. I was thinking of the LS2 just like you stated. Carry On.

Packy

iTrader: (11)

Hey thanks a lot guys. I had searched it on here and a few other GM forums and it looked like everyone said the same thing. Some argue about the cam sensor and knock sensors being in different positions but it seems that everyone is on the same sheet of music. Cool! I can't wait to start swapping stuff over and getting it into the truck!

budhayes3

iTrader: (19)

The cam and knock sensors are in a different position on the GENIV, which uses a cam sensor off of the cam gear, and knock sensors on the side of the block. GENIII engines get the cam signal off of the rear of the cam, and the sensor is in the block (as opposed to in the front cover on the GENIV), and the knock sensors are on the top of the block, under the valley cover which is under the intake. The GENIV engines also have a 58x reluctor wheel on the crankshaft for the crank position sensor, as opposed to a 24x reluctor on the GENIII engines. One is not compatible with the other, and would require a converter box for the PCM to able to read the crank sensor signal (available from Lingenfelter)

iamkeniff

iTrader: (16)

^^ 58x actually. the converter box is a must for the 58x into a 24x along with moving the knock sensor harness to the sides of the nlock which require drilling and retapping the block. i swapped a GENIV 5.3 into my 94 chevy using this method.

budhayes3

iTrader: (19)

Whoops, typo, fixed