[GaryL]

I have a 1989 S10 Blazer, 4.3L w/ 700R4 transmission. I bought the truck from a friend who had only owned it for a month before I bought it. The Blazer has 133K miles on it, and in December of 2002 the lower part of the connecting rod for #3 sheared. It wasn't until this past week that I was able to pull both the tranny and engine. The oil galleys are caked in crud, my oil pan looks like a sludge factory and scrapyard (thanks to #3). Many people say this engine suffered from both Penzoil and neglect. The VIN for this Blazer is 1GNCS18Z7K8106800. I separated the tranny from the engine today and will rebuild it later. All I have left to pull from the engine is the harmonic balancer, crank, and 4 more rods and pistons, along with the rest of the innards.
I know someone with a machine shop who will machine the block, redo the heads, and buy an engine rebuild kit at his cost to keep his volume high at the FLAPS all for $830. It's my first engine rebuild, so I don't want him to shortblock it, because I want to know my machine inside and out. I relish a challenge and I am very religeous about maintaining my ride. Same goes for the transmission.
I'm not out to build a hot rod screamer, just a truck that will tow when needed and be a good hauler and daily driver. I'm thinking mild cam, roller rockers, and/or other mods. Anyone have some advice to send my way? I would appreciate any and all input. hil:

You can see pics of the intake when I disassembled the top end of the engine on July 4. http://www.icnet.net/users/partsbin/Blazer.html

 

[Captain Morgan]

well, first off if I remember correctly, the Z code in the VIN would tell me that is a TBI LB4 engine, which bacially means it has the worst cylinder heads available for the 4.3L (same as Syclone & Typhoon heads). I dont know if your thinking of porting and polishing those heads, but my advice would be not to bother and try and find yourself a pair of L35 heads (W code 4.3L) and clean those up. Even stock they will flow better than your current heads.

While were on the subject of heads, I wouldnt bother with full roller rockers. Unless your going to build a high-revving performance engine, you dont need them. Save yourself some cash and either go with stock style rockers or just roller tip rockers.

As far as cam selection, thats where it gets tricky since the 4.3L cam choices are not quite as plentiful as the 5.7L counter parts.

Before I or anyone else can suggest a cam, I at least need to know if the engine originally had standard lifters or roller lifters and if the vehicle is computer controlled or not.

 

[GaryL]

Yes, it has a TBI, which I plan to keep. I don't care for carburators at all, no matter what anyone says. The engine is equipped with stock rockers. I appreciate your advice on heads. I'd rather get a set from the local boneyard, or someone parting out a Blazer than get them rebuilt from the FLAPS. Mild cam is fine, but if there's no selection then I'll stick with the stock cam. Oh, I plan on performing the electric fan conversion and will get the HIPO alternator. If there any other information you need? I need to look for busted down S10s because I need some interior dash pieces and the duct (someone cut the duct to install an aftermarket radio). Oh, this also has A/C on it.

 

[Sueto2]

ALL 4.3 MOTORS FROM 87 and UP ARE ROLLER LIFTER MOTORS AND IT IS COMPUTER CONTROLLED.

TRY COMP CAMS THEY HAVE A CAM PART #09-415-8 ITS GOOD FOR LOW AND MIDRANGE POWER AND WORKS WITH YOUR STOCK COMPUTER, BUT ADDING A CHIP WILL DEFFINETLY HELP.

IF YOUR GOING TO LOOK AT OTHER PLACES, YOUR MOTOR IS COMPUTER CONTROLLED WITHOUT A BALANCE SHAFT, THOSE WERE 92 AND UP MOTORS. HOPE THIS HELPS.

 

[Captain Morgan]

ALL 4.3 MOTORS FROM 87 and UP ARE ROLLER LIFTER MOTORS AND IT IS COMPUTER CONTROLLED.

TRY COMP CAMS THEY HAVE A CAM PART #09-415-8 ITS GOOD FOR LOW AND MIDRANGE POWER AND WORKS WITH YOUR STOCK COMPUTER, BUT ADDING A CHIP WILL DEFFINETLY HELP.

IF YOUR GOING TO LOOK AT OTHER PLACES, YOUR MOTOR IS COMPUTER CONTROLLED WITHOUT A BALANCE SHAFT, THOSE WERE 92 AND UP MOTORS. HOPE THIS HELPS.

thats the cam I plan on using in my truck actually, .500 lift is pretty wild for a standard rebuild. the 412 cam has more power in the bottom end also.

oh yeah,

 

[GaryL]

On another S10 website, someone told me to get the early Vortec headers, because later ones won't work with my stock intake. I'm not looking for wild racing performance, just reliable performance. The cam looks fine and I'm hoping the broken rods didn't dig into the crank. I was thinking of an MSD ignition setup. What kind of chip does anyone recommend? As long as it's apart, I might as well change parts while it's easy.

 

[Captain Morgan]

On another S10 website, someone told me to get the early Vortec headers, because later ones won't work with my stock intake. I'm not looking for wild racing performance, just reliable performance. The cam looks fine and I'm hoping the broken rods didn't dig into the crank. I was thinking of an MSD ignition setup. What kind of chip does anyone recommend? As long as it's apart, I might as well change parts while it's easy.

yes, you cannot use cylinder heads later than 1995. the bolt configuration changed in 1996 and therefore your intake will not bolt up. 1992-1995 L35 (w-code) heads are your best bet.

im not familar with chips for naturally aspirated 4.3's, so i cant help ya there.

 

[GaryL]

OK, great. There's a great boneyard on the western part of Oklahoma City about 8 miles from where I work. They have lots of S10s, so I guess I will give them a shout to see if they have any trucks from 1992 - 1995 with 4.3L engines.

 

[Captain Morgan]

OK, great. There's a great boneyard on the western part of Oklahoma City about 8 miles from where I work. They have lots of S10s, so I guess I will give them a shout to see if they have any trucks from 1992 - 1995 with 4.3L engines.

if the engines are still in the trucks, look at the VIN number, there should be a W in the 8th position.

also, under the valve covers stamped in the heads you should find 1 of the following numbers
10238181
10077626
14099064
10240209

if they have 10144103, they should be the same heads you already have, so dont buy them.

 

[GaryL]

NJTy180, that information about the heads helps out a lot. I'd hate to buy the same style heads again. I bet I'd have to take the valve covers as well, right? I will just to be on the safe side.

 

[Captain Morgan]

NJTy180, that information about the heads helps out a lot. I'd hate to buy the same style heads again. I bet I'd have to take the valve covers as well, right? I will just to be on the safe side.

if you wanna get the heads off the block, your gonna have to

 

[GaryL]

I called all around the Oklahoma City metro area today and can't find anyone with S10's, Bravadas, or Jimmys in their wrecking yards. To add insult to injury, two of the cylinder casting numbers listed above are said to crack and are difficult to find. The fellow who has them in stock would charge $300 for a pair of rebuilt heads. I can get both of mine done for $120! I'll keep looking around, not to mention I'll get the weekly Bargain Post and look for someone parting out their ride. I need some dash parts as well. I appreciate all the info that's been provided!

 

[MINTSICK]

$300 for rebuilt W code heads isn't bad I don't think? You're not going to want to bother with the stocker TBI heads worked or not.

 

[GaryL]

$300 for rebuilt W code heads isn't bad I don't think? You're not going to want to bother with the stocker TBI heads worked or not.

Why do you say that? Please elaborate why the 'Z engine heads are so bad? I have to stick to a budget, yet I don't want to be screwed down the road. :jawdrop:

 

[Trancer]

Swapping out heads from an LB4 engine to a L35 engine is not a bolt on project. The bolts and intake is all lined up differently. The L35 has the best flowing heads but they are not interchangable without major machining which would cost you more than rebuilding the complete engine anyway. If you want high flowing heads then either port and polish them with a more aggressive cam or get aftermarket heads... Niether is cheap either.

 

[Captain Morgan]

Swapping out heads from an LB4 engine to a L35 engine is not a bolt on project. The bolts and intake is all lined up differently. The L35 has the best flowing heads but they are not interchangable without major machining which would cost you more than rebuilding the complete engine anyway. If you want high flowing heads then either port and polish them with a more aggressive cam or get aftermarket heads... Niether is cheap either.

dude, shut up, only after 1996. the 1992 - 1995 L35 head is direct bolt on like I said above. thank you, drive through....

 

[Captain Morgan]

To add insult to injury, two of the cylinder casting numbers listed above are said to crack and are difficult to find.

said by who? Joe shmoe repair guy?? id be interested to know which ones "supposedly" thats prone to happen on

 

[GaryL]

said by who? Joe shmoe repair guy?? id be interested to know which ones "supposedly" thats prone to happen on

The rebuilder said these are the ones that are prone to cracking:
10238181
10240209

Granted, there are a lot of Elmo Einsteins here in Oklahoma. I'm still searching for a wrecking yard with S10s, etc. I can't believe the one place, with 40-acres, didn't have any! :twak: :zipit:

 

[Captain Morgan]

The rebuilder said these are the ones that are prone to cracking:
10238181
10240209

Granted, there are a lot of Elmo Einsteins here in Oklahoma. I'm still searching for a wrecking yard with S10s, etc. I can't believe the one place, with 40-acres, didn't have any! :twak: :zipit:

well, im not going to argue about it, but thats the first i have ever heard of it, not to mention the fact that cylinder heads just cracking for no apparent reason is kinda weird in itself, BUT at least I can say neither of those numbers are the ones I have sitting on my garage shelf

Right now, the guys over on SyTy.net are egging me on to get a set of 96+ heads and do the conversion, but I just dont think I can swing the $$$ right now If for some reason I do, Ill put my L35's up for sale, but it probably wont happen as soon as u need them.

 

[GaryL]

Damn, I was just going to ask how much you wanted for your heads
He didn't say the heads cracked for no reason, just told me they tend to crack and are difficult to find. I will take your word for it and use the other two numbers as my search criteria. You've been very helpful.