SBC to TBI compatability

[68gmc780]

On the early TBI 350 are the heads machined the same angle where they meet the intake as the old carbed 350? Simply put,will the 4BBL manifold bolt onto a 1990 TBI motor?

[77dwh]

yes it will bolt on but you need to modify the center 4 bolts to make it work right

[kalbert]

Yes and No, the angle of the bolt holes on the 4 inside locations near the exhaust crossover passage are a different angle on 87 and up heads. You can hog out the holes in the intake so they match, but it could crack when you tighten it down, and might be prone to leaking.

[Tx Firefighter]

I've ground a many of them and never had any cracks or issues. All you have to do is take a die grinder and machine out the bolt holes to oblong them to a more upright angle. It's a 10 minute job.l