I had to change out the engine on my 96 S10 recently due to a cracked block in cylinder 6. There were two vertical cracks in the cylinder and I have no explanation as to why they were there. My best guess is that at some point in the truck’s history it was overheated. I’m thinking that the vehicle ran with the cracks for a while, but that they finally let go and allowed lots of coolant to get into the oil and cylinder.

This is a 96 2wd, so I looked for a replacement from 96-2000 out of a 2wd. There were a couple at the local junk yards and they ranged from $500-$650. I could have gotten a low mileage engine out of an Astro van for $450, but the owner of that yard told me about the knock sensor issue, and so I opted for a good low mileage motor from a vehicle the seller's wife had just wrecked for $325. Turns out it was a post 2000 model. It was also a 4WD engine, so I knew from infallible internet research that I was going to have to trade out the oil pan and the oil filter adapter.

Well, the internet is close, but no cigar. When going from a 4wd to a 2wd you have to change the oil filter adapter, the oil pan and the oil pump. The 4wd pump is too deep for the 2wd pan. If you’re going from a post 2000 motor to a pre 2000 vehicle, you’ll also have to drill and tap a hole for the larger pre 2000 knock sensor. There is also a coolant sensor on the LH head that is 2 wire on later years and one wire on earlier years. Fortunately, this is the same size hole, so it’s just a swap. And I noticed that on my “new” engine there was just a plug where the coolant temperature sensor goes next to the EGR valve on the lower intake manifold. This wasn’t a big deal to me since I was using my old intake with the updated spider.

I have to say that this was the worst experience I’ve had changing out a motor. The thing is just shoehorned in there and requires removing many components to get it out. I wound up taking off the exhaust back as far as the muffler, dropping the transmission cross member to tilt the motor/transmission to get access to the bellhousing bolts. Next time (if I'm ever so cursed) I would try jacking up the cab as obliquely alluded to in the FSM to reach these bolts. I had the A/C bracket, alternator bracket and water pump off mine by the time I pulled it. I couldn’t imagine doing the job with the brackets connected, unless you took off the front end of the truck, including the condenser. I had the upper and lower intake and valve covers off as well. I don't see how you could get to the 14mm bolts on the heads for the ground connections and the fuel line bracket with them on. In fact, the bolt for the fuel line bracket was probably the hardest bolt on the truck to get off. You really need a zero offset ratcheting wrench. I realized I had one only after I finally got it off.

And what is the deal with the mix of metric/SAE hybrid bolts? Now, I realize sizes can be close enough but I ran into situations where only a 3/8” would fit and where only a metric socket would fit. And I don’t have a rust issue here, so there’s no swelling. The other interesting thing was that between the two years of my truck and the year of the new engine, many bolt head sizes changed, especially around the alternator and AC bracket areas.

And if you ever do the lower intake gaskets, I recommend strongly that you rent the puller and spend the extra 15 minutes and pull the power steering pump pulley and bracket. The bending the bracket method requires you to tilt the manifold coming off and going on. It guarantees that if anything is left on top of your manifold that you didn’t see or clean off, it will fall into your intake. When I was shopping for a used engine, I talked with a mechanic who was selling one and told him my story. He shared that it is very common for even techs to drop stuff into the intake while removing the manifold.

And, if using the Fel Pro lower intake gasket kit, throw out the tube of RTV they give you. It is crap. I had done the intake earlier and when this issue arose, had to redo it. This Felpro silicone wasn’t holding much of a seal after just a few weeks and felt like dollar store RTV. It was nothing like the factory RTV that I removed. It just peeled right off. Get yourself some Ultra Black or Ultra Grey if you’re doing the lower intake.

Finally, after seeing the tons of corrosion and aluminum being eaten away by Dex-Cool, I went with the green antifreeze. I notice that in the GM FSM they want you to add two tables of stop leak into the cooling system. That inspires confidence.

 

Glad to hear you got things done.

Think about if it was a 4WD and you couldn't easily lower the back of the trans!! Plus you have the front axle immediately ahead of the oil pan!!

Ground straps and fuel line clamp come off best after you have moved the engine forward an inch or two while coming out and while going back in (well, not that damn fuel line clamp_.

Have no idea what you are talking about with bending the P/S pump bracket. As you said just take the bracket off the engine with the pump and zip tie it near the corner of where the radiator goes.

Yes, A/C bracket, alternator bracket, water pump, P/S bracket w/pump, and right exhaust manifold are good things to remove from the engine.

 

Wow! If my motor goes, I have already decided I will not replace the motor. That is why as soon as I heard how the LIM gaskets can fail and ruin your motor, I decided to replace them immediately.

As for bending the "bending method" for the AC/PS bracket, what I did was loosen all of the mounting nuts and bolts and slide it forward a bit. That was enough. I did spend too much time trying get at an almost hidden nut (or was it a bolt?) that is down low. But I got the LIM back on pretty square. I only wish I had heard of the idea of using the old LIM bolts with their heads cut off as guide pins.

As for the RTV, I sure wish I had known to use better stuff than what was supplied with the Fel-Pro kit. Dang it!

 

Dude that looks insane! How much power does it have and how much did it ultimatly cost? Also i plan on doing a procharger on my 4.3 do you think that would work?

 

Dude that looks insane! How much power does it have and how much did it ultimatly cost? Also i plan on doing a procharger on my 4.3 do you think that would work?