I've got a 97 GMC Jimmy 4x4 with a 4.3 Vortec in it that needs a new motor. I found a low mileage wrecked Blazer with a good motor, but it is a 2x4. What parts will I need to make the motor work in my Jimmy? Any problems I could run into with a swap like this?

 

There is no difference in the engines provided they are similar years. You want a 96 thru 97 engine for it to drop right in and hook up with no issues. You will need to swap over your oil filter adapter if you are getting a 2wd engine, but besides that...

If you get a 98-01 engine, they do not have the PCM coolant temp sensor near the t-stat housing like the 96-97 engines do so you would either have to drill/tap the lower intake or swap intakes.

And if you get a mid-02 through 05 engine, they do not have an EGR valve or the PCM specific coolant temp sensor and they also have a different style knock sensor at the back of the block. With this scenario, you would have to drill and tap out the knock sensor location for the older style knock sensor as well as swap intakes to get the EGR valve and PCM coolant temp sensor back.

 

Thanks for the info. Another question, is there a gear drive conversion set made for a 4.3 with a factory roller and balance shaft? I found one for an older model 4.3 without those, but I haven't had any luck finding one to fit a newer 4.3 Vortec.

 

I doubt it. Before the balance shaft addition, anything from the 350 would swap over. But with the balance shaft, that goes out the window.

 

Just wondering, because the problem I'm currently having with my Jimmy is that it will not stay in time, and I don't know why. It went out on me about four months ago and I had somebody put a new timing set on it for me. It worked fine for 3-4 weeks and a thousand miles or so, and then went out again. I had it "fixed" a second time whole new timing set and oil pump this time, and two weeks later it left me stranded again. It has been tore apart in my driveway for over a month with me trying to figure out what's causing it to not stay in time. I was thinking a gear drive conversion might solve my problem.

 

Forgot to mention, after the last time it was fixed I noticed a slight miss/hesitation when pulling out.