I'm looking for input on a future project that I am seriously considering doing. Serious enough, that I almost told the junkyard to rip into a 2002 Tahoe to get the engine out for me the other day. But, I have more homework to do first.

I'm also posting this on the *-10 forum to see what they say, but it doesn't hurt to cover more areas eh?

Quoted from the *-10 forum.

5.7 will mount better if you already have the 4.3. You know, since its the same block just missing cylinders.

i doubt the 5.7 has the same mount. i would get 01-03 5.3 or 6.0 if i had the choice because the early ones had the head problems and after 03 is the drive by wire. you can run the later long block and get the upper end from 99-03 and pcm and everything else. the ls series has better power, mods, and efficiency. probably the same fuel requirements as your 6. your fabbing or buying custom mounts either way. there was a show on "trucks" about putting a 5.3 into a s10 blazer, you should check it out

04+ 5.3s also have an issue with the heads, mainly the 04s though because they built the PCV valve into the intake. I had a problem with mine burning oil at startup for a little bit. It seems to have cleared itself up.

Also, the 04+ are returnless fuel systems where as before they used return lines.

Ive been seeing many posts about how the 5.7 trans mount is identical to the 4.3 mount because the 4.3 was based off of the 5.7.

trans bolt pattern and all should be the same from 4.3 to 5.3 or 5.7 because they all used the same transmissions. just the engine mounts would be different

Mike i would check into what it would take to make it legal for inspection and stuff. Its still gotta be hooked up. Unless you got it registered like a custom built one.

Mike,

What is the motivation for the conversion?

As a S10 and Bravada owner, and former owner of a 84 S10, an a fleet of Astros' over the years, I have NEVER had a problem with a 4.3L other than the LIM gasket. The 4.3 is equivalent to the 3.8 in longevity.

I do wish the 4.3 was better on fuel. Other than that, it does everything I need it to do- flawless and reliable.

The PCM is already programmed to handle 8 different V8 engines. I only have to tell it which engine it is that I put in and it takes care of the rest. As far as NY is concerned, as long as all emission parts are installed, and OPERATIONAL, and the readiness monitors are ok AND there are no CEL, then I should be fine. From research I have done so far, I only need to add 2 wires for the extra injectors, and possibly another O2 sensor. But again, the PCM is already "ready" for it.



I haven't had a problem yet with my Bonneville in NY and technically, that L67 does not match my current VIN.

Same reason I swapped out my L36 for a L67. Because it can be done. And there are not too many V-8 *-10'* around here. Sleeper baby!!

if you put a 5.3 in it you will almost double the power and get better mileage

as far as inspection i dont think it has anything to do with the engine vin just the pcm vin matching the car. if you wanted to do a engine swap that required a different pcm that pcm would have to have your vin put into it.