plenum spacer

forcefed3.8's

Buckeye Bullet
Joined
May 26, 2002
I am considering a plenum spacer. Would it be worth doing with my combo? I plan on taking the engine to 6200 to 6300 next year. I have a Hemco upper and a fully welded and ported lower matched to a felpro 1200. I have no vacuum block. How high can I go, 1", 1 1/2"?
 
I am very curious of what you Hemco looks like on the outside. I am thinking that is what I must have. See the pic below. I am running a 1" Champion spacer and I have a vacuum block. The vacuum block does impring into my hood pad. I would venture to say that if I have a Hemco and you are not running a vacuum block, you would be safe below the hood pad - maybe right on it.

Let me know if this is what yours looks like.

Mike
 

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Not the stock appearing models. I have been reading and searching the board since posting on this thread. I thought my plenum was weird when I saw a square hold verses rectangular when I put the spacer in.

Additionally, I have a 70mm TB and they will not bolt up to a stock plenum. My up pipe is 3"OD and goes straight into the TB as seen in the pics.

Mike
 

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I have a stock appearing Hemco, just like the one you have. So without a vacuum block, I might be able to get away with a 1.5". I might remove the insulator anyway.
 
I have a 1" spacer with no vacuum block on top. The up pipe is whats hard to get clear of the hood liner.
 
Buy some silly putty or clay and put on top of your plenum, close and open your hood and measure the thickness of the clay. Worked for me.
 
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