I have a set of 14101081 heads that I want to use. The middle four manifold hold-down bolt holes (by the carb. area) are at a more upright angle than any other small block heads I've ever seen.

What factory Q-jet manifold goes with these heads? I imagine a 1986-87 manifold as that was the last year for carburators. What would the casting # be?

Thanks,
Bobby Z.

 

I'm pretty sure the 081 is a Vortec head, so you'll need a Vortec-specific intake that fits.

Just no idea if your gonna find a Vortec-pattern intake, with a Q-jet carb flange. Much more likely to find one with a Holley/square bolt pattern.

 

062 and 906 are the stock vortec casting #'s

 

OK. I wasn't sure.

 

It's not a Vortec pattern. 12 manifold bolts, not 8.

 

This sounds like the issue where the intake bolt holes are at a different angle than the bolt holes in the heads. There's many many threads on here about drilling out the intake holes at a different angle to match the angle of the head's holes. Not sure how to find them - maybe search "intake holes" and you'll see.

Seems to me basically they just wallow (a technical term) out the intake holes so that the bolts line up at correct angle to the heads. I want to think that the center valve cover bolted heads had a different angle on the intake bolt holes than the perimeter valve cover bolt heads, and thus most folks just take a drill and bit and 'work' the intake holes until they get the angle to match. Obviously (since many folks do it) the gasket takes care of the potential for leaks (since you've 'wallowed' out the holes to be more oval shaped than perfectly circular).

Hope that helps - search "intake holes" or something here and see what you find - posts should be in the general tech section I'd think.

 

081's have the center two intake manifold mount bolts at 72 degrees, and the rest at 90 degrees (like they all used to be).

The only years GM put carbs on those heads was '87 & '88 (and only G-bodies in '88).

If you want to use an '86-earlier intake manifold with those heads, then as stated, you need to modify the mount bolt holes in the intake manifold.

 

I don't want to just wallow out the center holes of an existing manifold. The shoulder of the bolt head won't sit square on the manifold.

I would like to know the casting # of an '87-'88 Q-jet manifold made for the center bolt valve cover heads.

Does anyone know of an intake casting #074?

 

081's are 87-92 305 TPI heads.

Go ahead and just slot the holes. A couple of washers under the heads of the bolts will help even out the clamping load. If you want to get REALLY picky about it, a few vendors sell inserts that adapt from one angle to the other, or you can buy wedges and try to adapt the angles. Really the center bolts aren't under a ton of pressure. People have been slotting the holes for years without a problem. You could always slot the holes and have a machine shop mill a flat seat at the correct angle for the bolt head, then you'd have the equivalent of any aftermarket TPI intake setup for both early and late heads.