While test fitting my FIRST intake manifold onto the engine block (with the end seals on), I noticed a gap between the manifold and the heads. I then tried the factory TPI manifold and same thing. I figure I'll use feeler gauges to find out what the gap distance is, take half that distance, add it to 0.060" (I had 1205s on), and get a set of gaskets that thickness. Do I need to add any additional thickness for a better fit and to compensate for gasket compression?

Passenger side, with gap


Driver side, no gap

 

Ditch the end gaskets and see how it fits. You don't use them anyway as a bead of RTV is preferred method.

 

Exactly. If that's an Edelbrock manifold they specifically say not to use end gaskets.

 

I will definitely get rid of the end gaskets. I originally tried fitting the manifold without the end gaskets, then I put them on to see if it would fit better. Unfortunately it did not make a difference.

 

The pics show 6 possibilities. The most likely is the block was decked, but not the "China walls". Or the heads were milled very heavily. Or both. Either way, swapping to offset dowels may be the easiest solution, but you then must check your valve-to-bore clearance, and re-check your piston-to-valve clearance. If there's not enough clearance, your next step is getting the "China walls" machined down. That means totally stripping the block.

 

You're right, the heads and block were both milled down. The pistons are 0.021" down the hole, the heads were taken down to 57 cc.

I'd REALLY hate to take the block back apart. Any reason I shouldn't try the thicker intake gaskets first?

 

If you attempt this without milling the china wall also , you run the risk of cracking the manifold when you tighten down the bolts ......

 

A cracked manifold would not make for a good day. Thanks

 

Well, turns out that when I test fit the manifold with OUT the cork end seals in place, I must have had some leftover RTV on there. I had not remembered that I scraped some off prior to installing the cork seals. Well, I removed the cork seals, and test fit the manifold one more time and no more gap (see below).

The bolt holes on the manifold were elongated at FIRST so everything should fit nicely now. I'll fully install it tomorrow. Thanks for the help.

Passenger Side


Driver Side


Very small gap between "China Wall" and manifold

 

Glad you got it sorted so quick, easy and cheap.