ZQ8Dude

I'll have to look into that.

L7 Sierra

The old S-10's never had a V-8 the swap is technically illegal, but I have seen a few cases where they managed somehow. Now the new Colorado has a V-8 option so technically it should be legal for all colorados to swap in such a motor.

Now for a point of fact everyones missed. You do not have to go to a referee station unless you get cought by a overly alert smog shop or your number gets pulled. So I would swap in your 4.8-6.0 LS motor, and hook it up to look factory. That means all the smog equipment and cats. The later LS's I hear have less smog so look there for your swap. I would even get the under the hood stickers for the 5.3, and call it a day.

Then when you need to smog
1. Do it right away. Don't wait till its too late to manuever the system.
2. Ask around at some of the independant smog shops/ repair places they maybe fine with letting your truck pass smog pervided it actually does. They won't report the motor swap, and thus claiming its still a 3.5. The test is based on Parts Per Million ratios so a 600 ci motor can put out the same PPM as a 2.0 the sniffer doesn't know the difference. It measures ratios not total volume.


I once got cought with a 406 sbc in my formally 250 6 cylinder 1977 Nova, and I never had a problem passing smog. They just gave me utter crap becouse it thumped pretty hard, and we had to argue a bit before I passed.

blue2003ls

iTrader: (11)

Like BlownChevy stated, now that the Colorado offers the 5.3 from the factory you just need an iron LS motor so they don't get suspicious. If you get all of the donor parts from a Colorado such as air intake, y-pipe and all the rest of the minor smog pieces it shouldn't be too hard to get your certification. The other caveat to the motor swaps is that passenger cars can be swapped into a truck as long as they are the same year or latter so the 6.0 and 6.2 motor are fair game as well.