'79 3.8 to '87 3.8 swap

[Jimmy87T]

Hello, all. I'm sorry if I ramble. I've got a '79 Century wagon with a tired 3.8 NA/TH350. I'm installing a 24,000 mile 1987 3.8 NA with a Monte SS 200-4R. The transmission swap is not an issue. I'm converting the '87 motor to a '79 so all the electrical and vacuum is plug and play into the '79 harness. I'm swapping the valve covers, exhaust manifolds, carburetor, distributor, and intake manifold from the '79 onto the '87. The '79 intake had two ports that were completely carbon-clogged...I believe them to be an exhaust crossover from #3 to #4. The ports on the '79 heads were also clogged. Here's the question: should I replace the intake manifold gasket with the '87 (fel-pro MS96037) which blocks these ports or the '79 gasket (which is the same as the '87 TURBO gasket, fel-pro MS96033)? I haven't pulled the '87 intake yet to look at the heads to see if there is even a port here or not. Are the heads that different between an '87 NA and an '87 Turbo? (I also have an '87 Regal Turbo T). Thanks for your input.

 

[anthonychacon80]

The fact that the ports are blocked on the 87 NA make me think that is the wrong intake gasket. The crossover ports for the EGR are there for the ERG to function properly. How else will the ERG get recirculated exhaust if not from the crossovers?

 

[Bweavy]

Hello, all. I'm sorry if I ramble. I've got a '79 Century wagon with a tired 3.8 NA/TH350. I'm installing a 24,000 mile 1987 3.8 NA with a Monte SS 200-4R. The transmission swap is not an issue. I'm converting the '87 motor to a '79 so all the electrical and vacuum is plug and play into the '79 harness. I'm swapping the valve covers, exhaust manifolds, carburetor, distributor, and intake manifold from the '79 onto the '87. The '79 intake had two ports that were completely carbon-clogged...I believe them to be an exhaust crossover from #3 to #4. The ports on the '79 heads were also clogged. Here's the question: should I replace the intake manifold gasket with the '87 (fel-pro MS96037) which blocks these ports or the '79 gasket (which is the same as the '87 TURBO gasket, fel-pro MS96033)? I haven't pulled the '87 intake yet to look at the heads to see if there is even a port here or not. Are the heads that different between an '87 NA and an '87 Turbo? (I also have an '87 Regal Turbo T). Thanks for your input.

The 79 heads are a different casting # 6291 for the 79 & the 87 are 8445's. The 8445's are the same turbo or NA. So if your going to convert you need to use the 6291 heads on the 79 intake & re-use the short block. You can look at the intake & tell it is about 10* off alignement. The best resolution is to get a 84 4.1 V6 4 barrel carb intake & put on the 8445 heads. The 84 4.1 used the 8445 heads as well.
Alot of guys here espescially olds Guys yanking 3.8's & 4.1's in there cars to do a V8 swap.

 

[Jimmy87T]

Well here is the 87 NA intake manifold gasket

And here is the 87 TURBO and 79 NA gasket

Rotate one 180* and I'm sure the bolt holes line up...the only difference is the center ports. If the 87 heads are all the same i should be able to use the 87 turbo/79 gasket. just rebuilt the 2 bbl and want to use It for now. Thanks!

 

[Jimmy87T]

Might keep the aluminum '87 manifold after all. Can anybody tell me what threads into this fitting? Passenger side rear next to PCV valve. Thanks.