John Millican's:

Swapping a LT1 intake into a 1st    Gen Small Block Chevy

 

People told me it won't fit. I asked more people, still no. Found a rumor one person has done it but I couldn't get in touch with him. I decided to try myself. I bought a used LT1 intake off of e-bay for $100 including fuel rails. Not bad, I figured if it doesn't work out I'm only out $100. Right?

You say it's impossible? Won't bolt up? Well your right but ANYTHING is possible when cost is a factor. Here's some of the biggest issues you're going to run into and a quick explanation of what to do about it. 

Problem #1, in case you haven't noticed there's no rear distributor on a LT1. I had to drill the hole for it, warning-this hole must be in perfect location. I used a old TPI base and made an aluminum template utilizing the
rear two mounting holes to locate the dist hole. Distributor must be shimmed about 1/4" higher due to the shortness of the LT1 intake. Also must use the small HEI distributor with remote coil found on 1987-later.

Problem #2, there are several problems with the STOCK LT1 intake but the ports and coolant passages are not one of them. What I did before I started was get a cheap $6 intake gasket from DAP and just laid it on the intake (already off the car), everything was perfect except for some of the mounting holes, the 4 corner ones were good. No problem, I took the gasket as a temple and drilled the new holes in the intake, no more
problem.

 
Problem #3, No front coolant passages to return to the radiator. Well, I just drilled and tapped two 3/4" heater nipples vertically where the coolant would normally exit the head. I will run 3/4" heater hose to a remote
thermostat housing I found on-line. it will be mounted on the fender well. It will use the same outlet neck and return to the radiator as it should.

Problem #4, must have custom fuel lines made to attach to the fuel rail of the LT1. About $40 if you supply the ends. Available from Pep Boys.

Problem #5, the was a temp sensor in the front of the TPI intake base, it's for the computer temp info. I will have to mod the remote thermostat housing for an additional hole.

 

Now for the detailed explanations 

 

Acquiring the parts

Modifying for the distributor

Modifying the bolt pattern

Modifying the coolant route

Modifying the fuel lines

Minor mods

Final pictures

 

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