This is where you start. I was lucky enough to
have a stock TPI base available to make a template from for the
distributor hole. It doesn't have to be a TPI base as all Gen1 SBC's use
the same distributor hole.
Here is the template I made from a piece of aluminum. It picks up the
last intake bolt on each side. I then used a pencil to mark the hole and
drilled it to 1 3/8".
A clearer picture.
Picture of the LT1 intake with the distributor hole drilled.
This is what I used to drill the 1 3/8" hole. It's called a
counterbore tool, start with a 1/4" hole and then go through with the
counterbore. I was able to borrow it from work as it is rather expensive
to buy for a one-time project.
Next you must address the distributor height issue. The Gen1 SBC intake
is 1/4" taller then the LT1 intake.
See the gap? This is the LT1 intake. You will have to make a spacer of
some sort. I had my neighbor turn a 1/4" thick aluminum washer 1
3/4" diameter with a 1 3/8" hole on his lathe. Unfortunately I
don't have a pic but you get the idea. |