I have a 91 formula ws6 with the lb9 engine. problem is someone switched out motors on me. I saw the numbers under the a/c pump and the last 3 letters were dda. I looked it up and it says its from a 86 lb9. question is, does this motor have a roller cam? it does not have center bolt valve covers. Also, I thought the heads were different for 87 up versus old style heads? So how would the intake bolt to it? It does not have provisions for a cold start valve and it does have a place for the map sensor. Help. I'm very confused. Thanks.

 

If its an 86 305 (and heads, sounds like) then it will be a flat tappet cam and have a one piece rear main seal, along with the perimeter bolt valve covers you already saw. The intake base can be modified to fit the earlier heads, that should be easy to see if its a factory intake.

 

The intake doesn't appear to have been modified. I really wanted a roller block. This sucks. But it should have a one piece rear main seal?

 

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Oh and what about the heads and all? Are they decent flowing? What is my biggest bottleneck right now? Also, are the stock injectors supposed to be a light blue?

 

The heads are decent enough if they're 86 305 heads, they'll be 416's. A decent exhaust would be a good and easy start to improve things.
The injectors were black on an 86 but yours might be from the 91 so they will be 2 colors. If they're just all light blue, someone changed those too.

 

The injectors are mostly blue but silver looking where they go into the manifold.

 

Those are probably the stock 91 injectors then.