Just built a 383 for my 88 IROC and dropped it in. Got the mini ram manifold from TPIS and am using a TPIS throttle body as well (which is the factory piece machined to 52 mm).

Question....... I know I don't ned all the factory vacume lines, etc...but are any really needed / should be used? I think I can plug them all but what does that do (if anything) to the Idle Air Control Motor and it's functionality? Would I be disabling the IAC by doing this? Would I get an engine light..? Not exactly sure how the IAC works.

Also, what about how the passenger side valve cover that has a hole that is routed right to one of the vacuum fittings on the passenger side of the t-body (the biggest one)? I have aftermarket valve covers with NO holes. I'll need to make my own wholes for PCV, oil filler, etc...for what I need / want? Should I make a hole and connect it to the t-body like the factory setup does? The thing is the Mini Ram manifold does not have a separate port (bottom center where it mates to the manifold - where the upper stock plenum did - factory ran this port directly to and down the runner's own ports & then routed to the lower manifold, etc..). The mini ram is just one solid opening for the t-body so all the separate spots on the factory t-body will all flow to the same wide open opening of the mini ram and right down the intake. I think running that line from the valve cover to the t-body may be senseless.

Thanks in advance for replies.

PS its been 2 1/2 years since I yanked the stock motor so I am really hating these vacume lines etc...:sillylol:

 

I do not have any experience with the mini ram. The vaccum line going to the IAC does not have anything do with its operation. I believe it is a switched vaccum source. Other than PCV you need to deal with the brake boost and fuel pressure regulator at a bare minimum. You are better off getting a maunal for the vaccum diagram.

I would ditch those valve covers if they do not have previsions for a PCV valve. If you bore the hole you will have big problems because there is no baffle. Stick the PCV valve in there and you will suck oil big time.