NOS TPI Plate Dimensions
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
NOS TPI Plate Dimensions
I purchased a NOS TPI Nitrous Plate and was wondering if anyone knew the dimensions of the openings? I'm going to place it behind my 52mm ASM Throttle Body and wanted to know the difference between the two...
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
Will it work, yes I'm sure it will. I'd prefer if the bores on the Throttle Body matched the bores NOS TPI Nitrous Plate. I am going to port match the plenum to the NOS TPI Nitrous Plate but it seems counterintuitive to slap on a Throttle Body with smaller bores.
From the information that I gathered on this and other forums the openings on the NOS TPI Nitrous Plate are 58mm, therefore a 58mm Throttle Body is in order...
From the information that I gathered on this and other forums the openings on the NOS TPI Nitrous Plate are 58mm, therefore a 58mm Throttle Body is in order...
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
NOS TPI Nitrous Plate layed over a AS&M 52mm Throttle Body
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
Disappointed that the bores don't line up perfectly
, a little more concerned that the bolt holes don't seem to match up either...
, a little more concerned that the bolt holes don't seem to match up either...
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Joined: Mar 2014
Posts: 571
Likes: 10
From: Indy
Car: 88 IROC-Z
Engine: GEN 4 LY6 (going forged 408)
Transmission: 60E (going RPM LEVEL 6 4L80E)
Axle/Gears: 7.5" 3.42 (staying...)
Re: NOS TPI Plate Dimensions
Break out the drill (and/or) drill press.
Joined: Oct 2001
Posts: 12,219
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: NOS TPI Plate Dimensions
The holes line up, just pic angle makes it look funky
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Joined: May 2008
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From: pawtucket RI
Car: 1986 iroc
Engine: alum. head 350 supercharged
Transmission: 6speed
Axle/Gears: ford 9in 3.90 35 spline moser axles
Joined: Oct 2001
Posts: 12,219
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: NOS TPI Plate Dimensions
They both point to the middle of the plate so the fuel and NOS will mix better.
Re: NOS TPI Plate Dimensions
Will it work, yes I'm sure it will. I'd prefer if the bores on the Throttle Body matched the bores NOS TPI Nitrous Plate. I am going to port match the plenum to the NOS TPI Nitrous Plate but it seems counterintuitive to slap on a Throttle Body with smaller bores.
From the information that I gathered on this and other forums the openings on the NOS TPI Nitrous Plate are 58mm, therefore a 58mm Throttle Body is in order...
From the information that I gathered on this and other forums the openings on the NOS TPI Nitrous Plate are 58mm, therefore a 58mm Throttle Body is in order...
Slap it on there and enjoy hauling the mail.
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
NOS TPI Plate layed over a TPIS 58MM Throttle Body
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
Any thoughts on the misaligned bolt holes?
Joined: Oct 2001
Posts: 12,219
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: NOS TPI Plate Dimensions
See which one fits ok on the plenum.
Joined: Sep 2005
Posts: 1,917
Likes: 326
From: NJ
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: NOS TPI Plate Dimensions
I just was working on installing my NOS tpi plate today and im noticing that my plate is a slightly different shape on the edes. my bolt holes lined up exactly, but I did not take a rear facing phto as posted above..
ALSO **** my plate came with engraved lettering on the one side stating "THIS SIDE TO MANIFOLD" AND*** the blue nozzle fitting is on the TOP and the red fitting on the bottom
exactly like this photo:
https://eb9239d2b3c1bda1d53d-6b4eb89...m/05151nos.jpg
or zoom in on the plate on this one.. https://www.holley.com/products/nitr...parts/05151NOS
that's what I have. the only thing about it I didn't like.. was the gaskets were a little oversized, so I'll just slightly shave/cut them down when I'm done with the install
*** Is my plate setup an updated version... or should I be worried that my plate IS different than the photos posted above ???
ALSO **** my plate came with engraved lettering on the one side stating "THIS SIDE TO MANIFOLD" AND*** the blue nozzle fitting is on the TOP and the red fitting on the bottom
exactly like this photo:
https://eb9239d2b3c1bda1d53d-6b4eb89...m/05151nos.jpg
or zoom in on the plate on this one.. https://www.holley.com/products/nitr...parts/05151NOS
that's what I have. the only thing about it I didn't like.. was the gaskets were a little oversized, so I'll just slightly shave/cut them down when I'm done with the install
*** Is my plate setup an updated version... or should I be worried that my plate IS different than the photos posted above ???
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
IROCZman15 - Thanks you for input! Indeed, you have an updated design, that is why your Nitrous plate & Throttle Body mate up perfectly. Mine is an older design, hence my problems 
Did you already bolt it all together?

Did you already bolt it all together?
Joined: Oct 2001
Posts: 12,219
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: NOS TPI Plate Dimensions
You shouldn't have any issues, it only goes on 1 way. Have you tried to put all the bolts through all the parts yet?
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
TTOP350- Do you have a part number for the plate in question?
Joined: Oct 2001
Posts: 12,219
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: NOS TPI Plate Dimensions
If you ment the 4.6, no I don't. I took it down after i looked at yours again. You have the correct part.
Have you tried to put the bolts through everything?
Have you tried to put the bolts through everything?
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
I sent the plenum to TPIS for porting (52mm to 58mm) it's scheduled to be shipped out today. I'll bolt everything together and snap some photos.
Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
Re: NOS TPI Plate Dimensions
Does anyone have any information as to why Nitrous Oxide Systems updated the plate design?
Joined: Oct 2001
Posts: 12,219
Likes: 1,141
From: Il
Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: NOS TPI Plate Dimensions
Probably changed suppliers or just wanted to freshen the design. Maybe they made a small change to something and this helps them identify the change.
Joined: Sep 2005
Posts: 1,917
Likes: 326
From: NJ
Car: 1987 IROC-Z
Engine: 406 on N20 w/ EFI
Transmission: P.B. 700R4
Axle/Gears: 12 bolt w/ 3.91
Re: NOS TPI Plate Dimensions
sorry I took so long to upload photos, busy time of the year.
however, here are the photos of what seems to be NOS's updated plate design. the one that came with my setup and is now installed on the car




don't worry, this winter I am going to buy a planned out assortment of -an fittings and probably run some of the feed lines differently. possibly under the plenum


however, here are the photos of what seems to be NOS's updated plate design. the one that came with my setup and is now installed on the car




don't worry, this winter I am going to buy a planned out assortment of -an fittings and probably run some of the feed lines differently. possibly under the plenum


Thread Starter
Joined: Jun 2009
Posts: 863
Likes: 33
From: Bellflower, CA
Car: 89 Formula, 85 Trans AM & 91 Bird
Engine: 5.0 CARB, 5.7L TPI & 3.1L V6
Transmission: T-5/700R4/700R4
Axle/Gears: 9 Bolt & 10 Bolt X2
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