1990 4.3 to Vortec 4.3 swap

[CatriderF7]

OK, so I was looking for an engine for my 1990 Rinker. Found one at a salvage yard, paid for it over the phone, they pulled the engine and I drove 2 hours away to get it today. When I got there it was a vortec out of a 93. So I just took it home and started pulling it apart. and am wondering what all Ill have to buy to make this work. First thing I noticed is the old style intake has what seems like a hollow pan riveted into the bottom of it that hits on the balance shaft. If I remove this pan will this intake work on the newer style engine? And will the older style distributor work on a vortec, balance shaft engine? I know ill need an electric fuel pump now but thats easy enough

 

[CatriderF7]

After looking around some I see that the vortec intake manifolds for carbs have that same pan on the underside except its not as deep, its more of a flate plate on the intake. So i would think maybe I could remove the deep one on my intake and replace it with a flat one, and as long as it clears the balance shaft I should be good? Unless theres actually something in that pan. But it does have 2 holes in it so I know it doesnt seal gas. coolant, or air in it.

 

[cliffblue]

Hello, having just gone through the top of my 2001 Vortec 4.3, I believe the intakes are not interchangeable. I'm not sure when they changed the bolt pattern, but they won't swap. Good luck, Cliff

 

[CatriderF7]

The bolt pattern is the same. I think since its an early vortec its still the same. They didnt change the bolt pattern til 96 I think. Both of these intakes have the 12 bolts that go into the head at an angle, not straight up and down

 

[rodgeml1]

If I'm not mistaken, the 1993 4.3L weren't true Vortec engines. They just had "Vortec" on the valve covers. I don't think they went to true Vortec internals until 1996 or so when they went from the 12 bolt to 8 bolt intake manifolds.

 

[Volphin]

Yep, the heads should have kidney shaped combustion chambers.

 

[CatriderF7]

Im not sure as far as internals go but it has the balance shaft and the 2 piece upper/lower aluminum intake manifold that says Vortec on

 

[CatriderF7]

Well I was going to just remove and modify that heat shield on the bottom of the intake that was preventing me from being able to put the older intake on the balance shaft motor. But when I pryed the heat shield back a little I could see the actually intake casting bows out almost as far as the heat shield, so I just ordered an intake off of a vortec motor with the 12 bolt pattern, and it is flat on the bottom side.