Hello

New to Blazers and chevy platform in general. Looking to replace both the engine and transmission in a 2002 ZR2 Blazer 4.3 Vortec with an auto trans.

Just reaching out to get insight on compatible 4.3 engines and transmissions - i.e. will any 4.3 vortec work, if not what years or engine codes, likewise for the transmission.

Other tips or important info welcome on this replacement. Thanks a lot

 

So, You want to read your VIN to start with, Dashboard on the drivers side, there should be a little notchout in the windshield glass edge paint that outlines it. Count 8 letters in, probably will go 1GNDT__- and then the 8th will be a W or an X, Either will work but you have an 8th VIN W you dont want an 8th VIN X block because its a slightly less powerful motor to my memory and understanding. Any block before 2001 will not work quite right as you will have to relocate the knock sensor to the passenger side cylinder head, whereas its on the back of the block normally.

For the Tranny you will need to tell us if its 4WD or not, Outside of that any 4L60E from 1999-2005 will work, I cant say for sure if any after that will work, and a sure thing is to check the connector color and case tag (if its still there) or the case stamping to get the exact year range/model of tranny.

Welcome Aboard, Know you've jumped into a whole new world of diagnostic insanity that it takes to keep this rigs running. Hope you enjoy your stay!

 

@Mods

Awesome information, thank you very much. I haven't looked at the VIN yet but I will keep that in mind. So, pre-2001 engines are really only "incompatible" due to the knock sensor location difference? Other than that, it'll work fine? The chance of me finding a 20 year old engine in a year range of 2001-2002 is going to be difficult probably... even for the once most popular V6 engine in the US of A.

Yeah the Tranny is 4WD, Automatic. So, 95-05 will be fine?

Thanks a lot for the help!

-Regards

 

Hi! i’m so sorry this has nothing to do with your post but i have a question that i cannot find an answer to.
i have a 2002 chevy blazer with tire size p235/75r15

i’m looking to get bigger tires but i don’t want to change the rim size right now. can i do that/what’s the biggest size tire i can go without it causing problems?

 

as the OP has said, he is new to blazers and cheverolet vehicles in general. Generally speaking you can run a 30 inch tire MAX without rubbing or issues. your truck may have suspension sag or misaligned steering which could cause rubbing, but you would know if either was the case. Please next time create a thread for the topic in the appropriate sub forum.


2001-2014 technically can work, these motors came in Silverados, Vans, S10s, and many other GM light duty trucks and vehicles, there were tens of millions of them built so you absolutely can find a motor, Most you may run into its accessory drive, oil pan, and lower intake stuff, which you can swap over from your old engine. put NEW oil cooler lines in while you have the ease of access to do so and make sure the cooler gets flushed, tranny cooler too once you put a tranny in. 4WD 4L60Es have a shorter output shaft to my knowledge so as long as its a 4L60E-there were two, one not electronically controlled but with a removable bell (marking it as a 4L60) and those with an electrical hookup, your truck will need an -E Variant. Just match up the type of output shaft for 4WD and the case code so you know its compatible, you also need to account for the input shaft and bell housing arrangement, for instance Colorado and Inline 6 TrailBlazer 4L60Es have a completely different setup. You may also want to consider just having the tranny rebuilt by a reputable shop.

 

thank you. i’m sorry as i’m new as well. joined yesterday looking for some answers, still not sure how to work my way around here. but thank you for the help.

 

Other things i forgot to mention, Usual engine swap parts apply, pull a rod and crank cap, check the bearings out, throw a new set in if no grooving is found that would require machine work as its super cheap insurance. cleanup the engine bay, repair any firewall rust if present, double, triple, and quadruple check your wiring, vacuum hoses, and the routing of them.