I have a 110mph speedo in my IROC that I want to swap out for a 145mph unit. The speedo is currently cable driven and its drive gear in the tranny is red. Will I need to change the drive gear too, or will I have to switch over completely to a tranny mounted VSS/wire driven speedo combo.

If anybody has any parts for sale that i can use for this swap, please let me know at iali@hotmail.com

I basically need the whole intrument cluster since I only have a Cyberdyne digital display that I'm hoping somebody here will want.

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'88 IROC 305 TPI
Gutted airboxes
160 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel
Ram-air setup coming soon
Flowmaster muffler
Taylor SpiroPro wires
Accel cap and rotor

 

All you need is the speedo head, you won't have to change the gears in the transmission.

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1984 Silver Z28, decked 383 cid 4 bolt, ARP Fasteners, 2 1/2" Cowl Induction Hood, 600 cfm Performer Carburetor, Torker II Intake, Performer RPM Heads, XE268H Cam, Magnum Roller Tip Rockers, MSD6AL Ignition, Blaster2 Coil, Recurved HEI Distributor, 700R4, TransGo SK, 2.73:1 Limited Slip Dana 44, Terminator Headers, Custom 3" TIG Welded Stainless Exhaust, Flo-Pro Twister Muffler, 4 Wheel Disc Brakes, Oil Cooler

[This message has been edited by Apeiron (edited November 25, 2000).]

 

You only need to change the drive gears in the tranny if you change rear end gears or tire size.

All speedos are calibrated on cable rpm. At 60 mph the cable is spinning the same speed with the 110 or the 140 speedo. The speedo itself is calibrated to display 60 mph at that cable rpm reguardless of what the speedo range is.

If you change rear end gears or tire size then the speedo rpm won't reflect the true speed of the vehicle.

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Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
454 Big Block buildup now in progress for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car
91 454SS daily driver
95 Homebuilt Harley

 

Thanks. Anyone else?

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'88 IROC 305 TPI
Gutted airboxes
160 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel
Ram-air setup coming soon
Flowmaster muffler
Taylor SpiroPro wires
Accel cap and rotor

 

What do you mean anyone else? Their info is correct.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

I think he means Does anyone have the parts he needs

But yes, they are correct!



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85 Z28 - Daily Driver
60 Ranchero - Project ( Money Hole )

 

hehehe...

 

Yeah, I mean does anybody have the parts? All the info in the world isn't gonna do me much good if I can't use it. I appreciate the help anyway. Thanks guys.

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'88 IROC 305 TPI
Gutted airboxes
160 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel
Ram-air setup coming soon
Flowmaster muffler
Taylor SpiroPro wires
Accel cap and rotor

 

Everybody wants to upgrade their speedo, so you need to get lucky and find one.

 

I may part with the one in my race car some day. It's metric but still goes to 145 mph. Right now it just fills the hole in the dash.

 

What year did they change them? I may be able to get ahold of one of the older ones, like in my 84, shoot, the guy I know may even have one of the newer ones by now, I haven't been out there for quite a while!

If he has one, I can prolly get one for about $50 for the whole cluster. That's a guess though, I forget how much I paid for mine.

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Working on:
'84 Z28 LG4 305
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350
using primarily GMPP parts.
Block is in shop!

Awaiting results from all 8 ASE tests.

Starting to look like the Kicker poster child!

 

The whole cluster for $50? Hell, dude let me know if your guy has any more . That would be great. As long as the VSS is mounted on the speedo head, everything's cool . BTW, the rest of the cluster will work fine with my sending units, wont' it? I don't think any of the sending units have been replaced with other parts yet.

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'88 IROC 305 TPI
Gutted airboxes
160 degree T-stat
Advanced base TPS voltage
Relocated IAT sensor
Momo steering wheel
Ram-air setup coming soon
Flowmaster muffler
Taylor SpiroPro wires
Accel cap and rotor

 

I know 86 was when they changed them in Camaros, as I found one in an 86 IROC at a junkyard. I dont know about Firebirds. Just remember 82-89 is one style, and 90-92 is a different style, in the Camaros.

 

Hey you should check out thirdgenparts.com those guys might have all the parts you need to do the swap, they got really good parts, just drop them an email and see what they say. I ve dealt with them and always have gotten great service, drop them a email.

 

I may make it out there this weekend. Actually, it is just a couple miles down the road, on the same road I live on! I just work too many hours to be able to get there when he's open! Luckily he's open 7 days, so maybe I can get out there.

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Working on:
'84 Z28 LG4 305
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350
using primarily GMPP parts.
Block is in shop!

Awaiting results from all 8 ASE tests.

Starting to look like the Kicker poster child!