I'm tempted to eliminate the isolator bolts.

[MrCreosote]

The only purpose of these is to suspend the intake in rubber to make it quieter. I don't think there are any thermal expansion issues.

The LS1 does not use them.

My only concern is that if the manifold is designed to float on rubber, you can't really draw the manifold down until it contacts the head - there is probably too much gasket rubber to allow this.

In this case, you would be torquing bolts to maintain a given rubber load which may not be enough to keep the bolts tight.

I'm still trying to determine if the Dorman kit is new, revised parts or just a set of the old parts.

Tom

[OldFaithful]

The lower intake manifold, which is metal, actually does connnect to the heads. The lower section of the upper manifold does not mount to the heads but mounts to that metal lower intake manifold with six standoff bolts with seals. The seals keep unmetered air from slipping into the manifold preventing a lean condition, and in my experience, at idle or low throttle settings is where it shows up setting the lean bank codes while idling at a stop light. The original ones reacted to the engine oil and shrank a little and need to be replaced with the new ones that do not shrink in the presence of engine oil. The oil gets in there through the PCV valve and associated pipeing. I don't see how you could get away with not having a good seal at those six mounting bolts. The top half of the upper manifold mounts to the lower part of the upper manifold, the one held inplace for those six bolts.

If there is a way to not use those seals, then you are going to be a popular person. Good luck.

Jim

[12Ounce]

What might work, if one was game for experimentation ... is to reused the old (shrunken, hardened) isolator bolts, but only after "wrapping" the seals with a generous coating of grey RTV. The bolts could then be installed first at a very low torque ... say 2 - 3 NM's ... and then after a curing period (say overnight) final torque to the specified 10 NM's.

Anyone game???