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View Full Version : will 350 TBI heads fit a 350 non-TBI block?


uglychevyZZ4
08-24-2006, 07:49 PM
heads from a 1990 350 TBI, will these heads fit on a older non-TBI block?
-and if they will, will the old carb intake fit still?

38377k5
08-24-2006, 07:52 PM
All SBC heads bolt up the same. If your valve covers have centerbolt valve covers (and subsequently the newer designed 8 bolt (I think?) intake manifold) the intake is different. If the bolts for your valve covers are around the perimiter of your valve covers then the older style will work.

uglychevyZZ4
08-24-2006, 07:54 PM
no theyre center bolt..

38377k5
08-24-2006, 08:06 PM
Then heads and exhause manifolds will bolt up, intake & valve covers will not.

uglychevyZZ4
08-24-2006, 08:19 PM
can the carbbed intake be modded to fit the TBi heads on the old old style block?

38377k5
08-24-2006, 08:23 PM
You can technically drill and tap newer model heads to accept older intakes but the intake ports will not line up correctly and it will cost you some power. I would buy an intake that matches the heads.

fatbob
08-24-2006, 09:22 PM
I put a pair of TBI heads [1986-1995] on a 1976 SBC and had no problems with the intake ports lining up. You'll need a new set of centerbolt valve covers, and you will need to work on the two center bolt holes on each side of the intake manifold. If you screw in the bolts without the intake on, you can see the angle you need change on the manifold, then just use a gob of silicone around those bolts upon assembly.
I think what 38377k5 may have been thinking of with the 8 bolt intake and ports not matching, would be the later model vortec intakes.
If you put a rv cam in with the TBI heads, you should see a Big improvement in performance, at least I did.
Good luck
Bob

b454rat
08-25-2006, 06:29 AM
I had two trucks with the TBI heads on an older block, both 400s actually. One was carbed, PO elongated the center two holes, and the other was TBI still. But they both bolted on and both ran great. The Vortecs are the ones that require a different intake, tho I've heard that you can drill and tap them, but not crazy about that idea, and the ports don't line up.