Hey all. I inherited a basket case and I need some opinions...

Vehicle is a 1996 blazer 4wd with the 4.3

Kid threw a rod through the block (apparently he didnt notice the rock that took out his oil pan or the oil pressure dropping to 0...but thats another story) he then went and bought a 93 short block from a junk yard, had it rebuilt by a local engine rebuilder. My mechanic pulled the old motor, did a valve job and resurfaced the heads from the 1996 in the mean time.

We got the motor back from the shop and the intake manifold dont bolt up (1/4 inch gap all around) apparently due to 93 vs 96. Also I read on another forum that the 93 didnt have a crank position sensor. Well the rebuilt motor we got back came with a timing chain cover that has a socket for the sensor but I dont know how to tell if its right (or maybe the rebuilders just stuck on the 96 timing chain cover because we told him it was going in a 96). I think the only thing else was no place to bolt up the power steering pump...

My mechanic (backyard variety works fixing heavy equipment/forklifts/trucks as a day job) says he thinks he can mill a shim to get the intake to bolt up correctly and put together a bracket of some sort for the power steering pump.

What we dont know is how to tell weather or not this will work (i.e. does the crank position sensor rely on machining on the end of the crank, magnets, something else...will the electronics from the wiring harness work with the rebuilt 93... is there more we're going to run into as we get into it deeper that will make it impossible...mostly, are we wasting time and effort trying to polish a turd....)

I talked to the junk yard and they'll swap what we have for a used non smoker but I would rather put the fresh motor in (obviously) if there's a way it'll work...vs a 90 day warranty on an unknown POS


So now its in my yard (motor in the cargo space) awaiting the sage advice of the gurus here (and please dont say cover the whole mess in gas and start pitching matches...)
Any help, advice or pointing in the right direction would be greatly appreciated...should I cut losses and deal with the unknown non smoker or do you think if I hit it hard enough can I get this square peg to fit in the round hole???

 

You are MUCH better off getting the proper 96+ engine to drop in than trying to mess with the older block/heads.

The CKP sensor is triggered by a reluctor ring on the crank. Not sure that the ring from a 93 has the proper number of teeth and the proper gap to the sensor. Again, you are much better off using the proper motor for the application.

The next problem will the be the heads and cam from the 93 motor. This combination may not run very well with the newer upper intake and stock PCM programming. It is quite possible that you will run into error codes from the PCM given the operational characteristics of the engine.

 

I have 2 vehicles with 4.3l a 95 and a 96 - I just recently put new head/intake gaskets on both and found out that they are definately not the same block. many components are the same like the lifters, but the blocks are not. My dad (30 year ASE mechanic) told me that the blocks were changed with the introduction of the Vortec line. In essence, you are fighting a losing battle with the 93 block.

A 93 is Generation 1, your 96 is Generation 2.

 

i always thought the blocks were the same , but the heads on the vortec motors were different than non vortecs....either way youll be better off find a 96+ motor like swartlkk stated.

 

The blocks are physically different, but not different enough that the short block could not be used as most of the differences are cosmetic and not form/fit/function related. Heads, no way with out some major modifications. And I do not know why you would want to use the heads. They do not flow as well as the 96+ heads.

 

Heads are from the 1996. Only the rebuilt short block was from the 1993. Is this a viable combination or did I misunderstand your above post?

I understand that the best answer is 1996 everything but as the kid (ex wifes son)who owns the mess is a single dad and short on cash I'm just trying to see if we can salvage the situation with parts on hand and some elbow grease or if it is a waste of time.
He's got $1200 +$150 for the core into the short block. Anyone need a fresh 1993 short block for $1200?

 

$1200 into a 4.3L short block??? What did they put in that, golden bearings and a silver crankshaft? WoW! Hopefully you can use it cause that is WAY too much money to have dumped into that motor. Heck, you can go grab a decent mileage engine from a 96+ at the junkyard for $300-$500.

If the heads are from a 96 (you never clearly stated that so there is no need for the emphasis), the lower intake *should* bolt on. I say *should* because I do not believe that the deck height was changed from the CPI motor to the SCFI motor so that should mean that the heads are the same distance apart. Not guaranteed that everything else will work right though. Should be a learning experience for you though.

 

3-500 sounds real good, but not around here. None avail locally (SW montana) and if U go as far as Spokanne, WA (350 miles) I can get one for 800 with 110k miles and a 6 month warranty.

As for over paying, probably. Most things cost to much out here in the boonies...

I know I didnt make it clear, thats why I edited the orig post. No offence meant. Just hoping a few itallics might get me an easier to stomach answer ... Thanks for your help.

 

Last question (hopefully):
I read on another thread that a 96 to early 02 would be a direct drop in replacement?
I have access to a 2000 4.3 for cheap but dont want to run into the same problems as above....

 

Same exact motor. The only difference is in the # of O2 sensors, but you are not changing the exhaust out so you should have no problems there. The 2000 motor would be a much better choice IMO.