[TanCalHan]

Hi, so my 91 S10 4.3 blew up. Injector stuck open and dumped over a gallon of gas into my oil pan going 60 on the highway. Engines toast. Crank destroyed and the rod bearings spun so bad it toasted the rods. I picked up a free low mileage 1985 4.3 from an el Camino. I plan to swap intakes and oil pans to get this into my s10. I know the el Camino engine is a flat tappet, oh well, doesn’t matter to me. My questions are, the el Camino 4.3 uses a two piece rear main, can I swap the one piece rear main oil pan over to the new (used) engine? Does the TBI need knock sensors to run because this el Camino 4.3 was TBI, but doesn’t have the knock sensors in the same spot as the 91 4.3 did. And are the grinds on the two different cams so drastic the 91 tbi computer won’t make it run right? Thanks.

 

[944v8indfw]

Dont think the oil pans will swap because of the seal difference. As long as you can use the 91 knock you should be good there, may have to extend the wire. Cams should be close both TBI so not many worries there. By looking online, the pans look real close might dodged a bullet there. Exhaust manifolds may need to be swapped over.

 

[TanCalHan]

Gotcha. I haven’t quite looked at the oil pans closely yet. Been so busy lately. Only think I’m concerned with really is the oil pan. They never made a two piece 4.3 in the 4x4 anything. I’ll probably have to extend the knock wires, but do they need knock sensors to run efficiently? I know if I unplugged the knock on my friends 03 5.3 truck it wouldn’t run right at all, but these TBI’s are more conducive to just running even if sensors are bad

 

[oldeerslayer]

You can not use a newer 1 piece seal pan on an older crankshaft. Not even close. They do make adapters to use a 2 piece crank in a newer block. It just bolts on in place of the late model seal mount. Problem is you want to do the reverse.
Never seen an adapter for that and don't see how you could make one because the later seal is outside of the block. The 2 piece is actually in the rear main part of the block and bearing cap. You're really need an 86 up engine since you have a 4wd with the extended depth pan.
I suppose you could cut the bottom off the newer pan and weld it onto the top of the older pan. If the extended oil pump pickup tube can be made to work. It should since the oil pumps didn't change. Trick is going to be getting the metal clean enough to tig weld on 2 old dirty pans. I did one for a V8 swap and got a couple pin holes, but was able to cure them with a little JB Weld on the outside of the pan. There isn't any pressure involved in a pan. So simply plugging the holes worked.
Put the knock sensors on it. The computer works a lot better with them. Other wise you run the risk of too much advance and detonation can kill an engine. You can actually burn holes in the pistons.
In the old days you'd advance your timing until you heard the pinging, then retarded it a bit. The computer does the same thing. Only your wanting it to do it with a deaf computer.

 

[TanCalHan]

Thanks for the information. Probably going to find a newer engine so I don’t have to deal with the pan hassle. I appreciate it