I have a 2001 Chevy Blazer with stock 4.3L (262) SFI V6 (Vortec) engine. Had transmission and engine problems which both had to be rebuilt. My son owns it now and we just want to put rebuilds in it to get it back up and running for his first car. We have the tranny almost complete with a rebuild. Needing to find a engine that will be a direct swap, hopefully, that we could rebuild. This is supposed to be a fun, father and son project for us to do. the old engine is cracked between water jacket and cylinder head and cant use. Need to find an engine that we can use as a core to rebuild and move our aux items over to it. I know the original engine was used in many different years, makes and models. Does anyone have any information or advice on what years, makes and models would work for a direct swap? Thanks for any help/advice!!!!!

 

If you're looking for a short block (keeping your head s and manifolds), almost any GM truck 4.3L "Vortec" engine will work as a core. If you're swapping a complete engine, you want to match the RPO code and VIN character. Yours should have a "W" in position 8 of the VIN and the RPO code "L35" on the sticker in the glove box.

These engines were used in S/T series pickup trucks and SUVs, full sized 1500 series pickup trucks, Chevy Express and Astro vans and GMC Savana and Safari vans.

A good resource for interchange info and a good start for looking for used parts is Car-Part.com--Used Auto Parts Market . The interchange info there is better than the "inventory" information provided by the member used parts vendors. Generally speaking, I've found parts on there with fewer than 10 phone calls, often in the first 3 or 4 calls. It's common to hear "we don't have that one any more." Most yards don't keep their inventory current on that shared database site.

One thing not shown in the interchange is oil pan compatibility. If you threw a rod through the oil pan, you'll need an S/T series donor which matches your drive train (2wd or 4wd). If your old oil pan is good, it will bolt to any engine that interchanges, but if you need a replacement pan, it has to match your drive train.

 

Don't forget about metric vs non-metric threads and different pad on top/rear of block for knock sensor. Knock sensor change to later style was in 2001 if I remember correctly. Also unless you want to have engine balanced and/or potential mismatches you need to be aware of heavy vs light rods/pistons, different cranks, different balance shafts (or lack of balance shaft), differences in valve rockers, different cam bearings, and different factories of origin (Totawanda vs Romulus) when dealing with the engines from the 1990's.


IMHO to avoid all problems you should be looking at vin W engines from 2001-2005 in the Blazers and vans. 2003-2005 would be LU3 code (MPFI injection). 2001-2002 would be L35 (CPFI). All of these should be identical mechanically except for the camshaft specs itself. Any replacement parts for the rotating assembly should be very close in weight/design to those that you take out, so be careful when choosing pistons and any replacement rods and don't throw you old parts away too quickly. To be safe, cranks used should only be for the engines from the 2000's.