? Year of change on lower intake?

[chestatee]

I need clarification on "what year did GM change the lower intake bolt mounting hole angle into heads? What about the exhaust manifolds, any changes with mounting angles? I have access to parts on a late model engine, but need to put parts on a 95 6.5 td.
Thanks

 

[handcannon]

This is not definitive, but to my knowledge the difference in bolt angle has nothing to do with year. Instead it is related to whether the motor was a passenger side exhaust manifold mount turbo, or a center mount turbo. All the side mount turbo motors I'm familiar with have the intake manifold bolts going into the head at a right angle to the heads intake surface. The center mount turbo motors have the manifold bolts going into the head intake surface at a right angle to the crank center line (vertical).

To my knowledge the exhaust manifold bolt orientation never changed.

Don

 

[chestatee]

Thanks Don
Good info.

 

[ak diesel driver]

Could be wrong but I think the NA vans have the same heads as the center mount turbo ones.