Here is article from Popular Hotrodding magazine on the TPI Intake swaps with cooling problems. The link to the article is at the bottom. The jist of it is trapped air and no coolant crossovers.
You shouldnt have to use a helicopter to cool your radiator. The issue is still there, hope this helps.
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As mentioned in the story, the factory LT1 intake does not have provisions for a thermostat, housing, or coolant crossover between the heads. Because of this, provisions must be made to ensure proper cooling is maintained. One way is to use the remote mount thermostat housing, which I mounted on a bracket I fabricated that bolts under the driver's side STB brace. I used the factory TPI thermostat neck and upper radiator hose, which was flipped over and shortened, to provide return flow back to the radiator. The remote housing needed to be drilled and tapped for four (4) holes: three (3) for the coolant lines and one (1) for the coolant temp sensor, which is factory mounted in the TPI base. The coolant crossover lines were tapped from the rear of the intake instead of the front like the factory to provide more room for the throttle body and associated linkages. I used 1/2 NPT to 3/4-inch nipple fittings on the intake and the housing. The 3rd fitting in the housing should be plumbed back into the factory diverter valve and replaces the stock coolant line that came out of the factory TPI base manifold. It is important when mounting the remote housing and routing the coolant lines that the radiator cap remain at the highest point in the system to avoid getting air trapped in the system during normal operation. Upon initial start up we had to "burp" the system to remove all the trapped air, so keep this in mind to avoid any problems.
Read more:
http://www.popularhotrodding.com/tech/0803phr_tpi_intake_conversion_ls1/index.html#ixzz1cYLtIjJZ
