[BillK]

86 was right about the time GM started changing the angle on the center 4 bolt holes to clear the Throttle body on the TBI engines. If those four holes are 90 degree to the head then your old manifold will bolt right on. If the four center holes are tilted slightly you can "modify" the four center bolt holes in the intake to get the bolts to fit. Edelbrock makes some angle spacers to help but I have done a couple without using them and it worked fine.