It's a 1981 Chev SB pickup. I needed a truck; and didn't want to spend a lot of money so I bought this stripper of a truck. It has two rust problems (that are easy to fix) and seems to be well maintained. It's a 4.1 liter 6 cyl - that I'm so tempted to fix the carb problem with a V-8; however, the challenge of a new motor is really getting to me - so perhaps I'll give it a go before I dump the entire boat anchor - ahem - I mean fine piece of auto ingenuity.
Forgive the focus on the third picture.
I used an existing, plugged port for the new line. The Holley carb book I have said to drill directly from the back into the powervalve. But looking at the base on the carb body, I realized that there would be no way to get a line on there, and even if I did it would probably interfer with the carb bowl. The line that I use is covered by the base gasket so it is sealed ... I used a 5/32nd drill bit for the hole.
If you're copying this, just take your time... it goes pretty easily.
there is a good discussion elsewhere on this site about why boost reference.
The arrows on these pictures show where I drilled holes to get the vacuum port into the carburetor. I finished by using an anti-crush sleeve from a copper fitting for the hose line, and a 10-24 bolt with lots of lock-tite threaded into the original powervalve inlet
Weekend work changed the top end of the motor from the aluminum corvette heads back the 993 so I can run the blower on it again... same hp, lower octane (meaning I don't have to go the airport again to get some avgas to keep it from knocking.... was super lazy today, been doing the head change over 2 days now and still not done... and one random picture of it while doing bodywork. (it will look like this again since I do want the body to be "perfect").