fromt he pedal to the module there should be a small maybe five wire or so harness connecting the pedal to the module..

im trying to figure out where in the engine compartment the module monts to..over on gmfs i have no repsonse

 

i have it. it mounts on the drivers side upper of the firewall

 

ull see it

 

Do you know if the 5.3 in the 03 silverado are the same as the 03 express?

 

it should be. theres a huge difference when going from 99-02 to 03 and another difference when going 03-04+

another thing we noticed is the parking switch on the transmission is different, as well as the ac canister

 

The canister is i had to replace mine, and the switch like the neutral safety switch? is it 1 connector instead of 2?

 

yeah i kept my 6cyl one but we went the ac line out of the way of the oil dipstick. the yeah the switch on the side had one big connector vs 2 so we had to replace it.

 

Just wanted to jump in here again. I just successfully drove our 2001 Silverado ECSB home last night after swapping from the 4.3 to a 6.0 and 4l80e trans. It was definitely worth the work!

I picked up a mostly complete 2001 2500hd SCLB that was wrecked. I used the motor, trans, harness, ecu. I had to get a different yoke for the driveshaft, "merge" the fuel lines and trans cooler lines, cut out the crossmember mounts and drilled/bolted the 2500 trans crossmember to frame, and then do the security relearn.

Runs and drives great! Only code i have is for oxy sensor bank 1 sensor 2 cause it isnt there yet .

 

Ok i have read every post in this thread and i still have a problem that has yet to be brought up. I have a 04 rcsb 2wd silverado. Its a 4.3/5 speed truck or was anyway. I picked up a 2000 2500 6.0 and 4l80e to drop in it. The problem im having is the frame mounts. I know the 4.3 mounts wort work so i too them out and tried to put the 2000 6.0 mounts in but that isnt happening. I figured it was because of the 3/4 ton frame so i went to the junk yard and the only thing i found was a 03 5.3 2wd tahoe so i bought the mounts. Guess what lol the pass side will bolt in the the drivers side it a little over a inch to wide and the bolt hole on the frame are a inch wider than the holes in the mount. Im lost and thinking im just going to have to either build some to fit or order a set of 04 5.3 mounts from a dealer. I really dont want to go to the dealer so someone please help. Thanks

 

I ran into the same problem on my swap. You have to get the corresponding frame mounts as your vehicle. The drivers side frame mounts from a 2wd to a 4wd are different. I believe the 2wd is longer like the one your talking about. I ordered the 2wd for my 4wd on accident from the dealer but swapped it for the correct one once i figured out the error. They changed it to clear the front diff. on a 4wd. Hope this helps.