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I have replaced my original 350/350 with a 400 small block. I am adding all of the standard corvette parts to this new engine including the original distributor. My question regards the fit of the distributor into the intake manifold. I had a vintage z28 302 aluminum manifold on my 350 and have replaced it with the original cast iron manifold. The distributor seems too loose at the manifold, it was snug in the aluminum manifold. Is this a normal fit? thanks for any feedback.
I'm referring to the fit between the manifold and the distributor housing without the hold down clamp. My experience is that this is always a close fit. This is not the case with my situation, the distributor has room to move in the hole so I'm not sure it's centered when I clamp it down.
If your block was decked you may either need a slip collar distributor or if the gap isn't that big you can use the double gasket trick. You don't want to force it completely down if it doesn't want to go, it will chew the gears up.
I'm referring to the fit between the manifold and the distributor housing without the hold down clamp. My experience is that this is always a close fit. This is not the case with my situation, the distributor has room to move in the hole so I'm not sure it's centered when I clamp it down.
I believe you are referring not to the top where the gasket sits but the sides where the shaft slides in the hole. That should be a pretty firm fit and you should not be able to move it from side to side very much at all.I would not use that manifold as for some reason it sounds worn. Before buying a new one though i would confirm it by putting your distributor in the hole on a new manifold to be sure.
Thanks everyone. I think bluedawg hit it on the head. I did have the heads cut to improve the compression ratio. I think what I am seeing is that the housing is not seating on the manifold surface. I am experimenting with a combination of shims and gaskets to try to get something that looks reasonable.
does anyone know if there is a method to determine the proper depth of the distributor into the motor and the corresponding shim thickness between the dist. housing and the manifold?
does anyone know if there is a method to determine the proper depth of the distributor into the motor and the corresponding shim thickness between the dist. housing and the manifold?
Drop it down the hole, and measure the gap with a feeler gauge. Just add enogh shims to insure the body does not bottom out. A tad high is better than binding.
Are you sure that the end of the distributor shaft has engaged the slot in the oil pump drive shaft? If not, the dist will not go down all the way and will be about 3/16" too high.
Thanks for the replies. I am fully engaged with the pump, the distributor housing does not sit on manifold. The concern I have is that as I add shims to make sure it does not bottom out on the pump shaft I lose the pilot diameter on the housing and the distributor can move laterally in the hole. maybe it does not matter, I'm just being cautious not to damage anything in theis new engine.
Thanks for the replies. I am fully engaged with the pump, the distributor housing does not sit on manifold. The concern I have is that as I add shims to make sure it does not bottom out on the pump shaft I lose the pilot diameter on the housing and the distributor can move laterally in the hole. maybe it does not matter, I'm just being cautious not to damage anything in theis new engine.
The block holds/indexes the dizzy housing. The manifold just has a clearance hole. Don't fret on it. Add shims to get the clearance, then add one gasket. DON'T stack gaskets. They compress.
I went with one shim, .030" and one gasket for a total of about .125". I will run it a while and then check it for wear pattern. Thanks for the feedback everyone.