Cross threaded plenum

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Jul 27, 2020 | 07:02 AM

Ironmike77

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Cross threaded plenum

Anybody know what size tap I should buy, to retap the holes in the upper plenum?

Jul 27, 2020 | 07:58 AM

aliceempire

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From: Milwaukee

Car: 92 Firebird, 77 Trans Am SE, 86 Z28

Engine: 5.7 HSR, T/A 6.6, empty

Transmission: T-5, TH350, T-5

Axle/Gears: 3.08 posi, 3.23 posi, 3.23

Re: Cross threaded plenum

upper plenum are M8-1.25

Jul 27, 2020 | 08:03 AM

Ironmike77

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Re: Cross threaded plenum

Ok cool thanks! I just read a post somewhere that it was m8x1.5mm. But m8x1.25mm for sure right?

Jul 27, 2020 | 08:33 AM

aliceempire

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iTrader: (14)

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From: Milwaukee

Car: 92 Firebird, 77 Trans Am SE, 86 Z28

Engine: 5.7 HSR, T/A 6.6, empty

Transmission: T-5, TH350, T-5

Axle/Gears: 3.08 posi, 3.23 posi, 3.23

Re: Cross threaded plenum

yes, 8-1.25 is more common and I just had to helicoil one of my own. And 1.25 is the thread pitch, not length, reason I state that is you have 1.25"mm" listed.

Jul 27, 2020 | 08:34 AM

Ironmike77

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Re: Cross threaded plenum

Thanks! I’ve lost patience with installing these injectors!

Jul 27, 2020 | 08:04 PM

aliceempire

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iTrader: (14)

Joined: Nov 2008

Posts: 2,094

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From: Milwaukee

Car: 92 Firebird, 77 Trans Am SE, 86 Z28

Engine: 5.7 HSR, T/A 6.6, empty

Transmission: T-5, TH350, T-5

Axle/Gears: 3.08 posi, 3.23 posi, 3.23

Re: Cross threaded plenum

Quote:

Originally Posted by Ironmike77

Thanks! I’ve lost patience with installing these injectors!

I understand that feeling. Now try it with ported aftermarket stuff and find out you have vacuum leaks...repeatedly. I can only give sympathy to SuperRam owners.

Jul 27, 2020 | 08:13 PM

Ironmike77

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Re: Cross threaded plenum

Quote:

Originally Posted by aliceempire

I understand that feeling. Now try it with ported aftermarket stuff and find out you have vacuum leaks...repeatedly. I can only give sympathy to SuperRam owners.

Oh yeah it’s definitely irritating! And the leak is usually some hard to reach area in the engine bay haha.