140mph faces on original 85mph with 4.10's

stng87 · 03-14-2001, 01:57 PM

Ok I think I might have screwed up by installing the 140mph guage faces. i thought that surely i would be able to dial that correct mph in somehow, but the more I think about it the more I think it might not be possible without getting a whole guage cluster that originally had a 140mph speedometer then installing the right speedo gear for the 4.10's. has anyone else done this? Can it be done? I have an aod and my original guage face was 85 mph (85 was too boring)

QUIN · 03-14-2001, 02:01 PM

i dont know about the guage face,,,, seems like it would work fine. you will need to change your speedo gear with the 4.10's though, regardless what guage you run. it calls for a 23 tooth gear, but ive heard a lot of people prefer the 21 because the 23's are too thin and break easily. they say 21 is close enough. personally, i have 3.73's and they call for the 21.
Q

------------------
Quin, 87 GT,306,forged pistons,edelbrock head\intak,steeda#18cam,1.7rr,MSD Blaster tfi coil,A9L,pro-m75mm,24#inj,accufab65mm,2.5"pipes,hooker headers,dynomax exhaust,3.73 gr,110 lph fp,180*therm,moroso cold air,ASP pullies, weld rims

The beast has awoken!

I see your shwartz is as big as mine, now lets see how well you handle it!

Unit 5302 · 03-14-2001, 02:11 PM

Well, you're gonna need to have your speedometer recalibrated. The 1987's, like mine, come with 85mph speedo's, when you switch to the 140mph gauge faces you need to have the speedo recalibrated.

If the 23 tooth gear is weak, I'd just get the 21 tooth, and then have the speedo recalibrated.

stng87 · 03-14-2001, 04:13 PM

thanks quin and unit, any idea how much they charge to recalibrate and who does it?

slider · 03-14-2001, 04:45 PM

stng87, I have a question for you..
how are those 4:10 gears? do you have an auto tranny or 5spd?

i have been thinking about getting 4:10 gears for my 87GT 5spd

stng87 · 03-14-2001, 08:35 PM

i love my 4.10's, wouldnt trade them well maybe for 4.30's but probably not. I have a recently built aod. I was concerned about my gas milage as i am a pussy about losing too much of it, but I cant even see any effect on the gas milage. But in performance, thats a huge difference, even going from the 3.73's. In my experience, 373's are plenty in a 5 speed but I still think that 4.10's feel much better. Youll love it either way you go.
Care about gas milage=3.73's
dont=5.34's no no just joking. 4.10's
Hey anyone running 5.34's is that even a ford gear?

03-14-2001, 01:57 PM	#1
stng87 Registered Member Join Date: Sep 2000 Location: southern california Posts: 329	140mph faces on original 85mph with 4.10's Ok I think I might have screwed up by installing the 140mph guage faces. i thought that surely i would be able to dial that correct mph in somehow, but the more I think about it the more I think it might not be possible without getting a whole guage cluster that originally had a 140mph speedometer then installing the right speedo gear for the 4.10's. has anyone else done this? Can it be done? I have an aod and my original guage face was 85 mph (85 was too boring)

03-14-2001, 02:01 PM	#2
QUIN Registered Member Join Date: May 1999 Location: Chillicothe, OH. Posts: 1,289	i dont know about the guage face,,,, seems like it would work fine. you will need to change your speedo gear with the 4.10's though, regardless what guage you run. it calls for a 23 tooth gear, but ive heard a lot of people prefer the 21 because the 23's are too thin and break easily. they say 21 is close enough. personally, i have 3.73's and they call for the 21. Q ------------------ Quin, 87 GT,306,forged pistons,edelbrock head\intak,steeda#18cam,1.7rr,MSD Blaster tfi coil,A9L,pro-m75mm,24#inj,accufab65mm,2.5"pipes,hooker headers,dynomax exhaust,3.73 gr,110 lph fp,180*therm,moroso cold air,ASP pullies, weld rims The beast has awoken! I see your shwartz is as big as mine, now lets see how well you handle it!

03-14-2001, 02:11 PM	#3
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Well, you're gonna need to have your speedometer recalibrated. The 1987's, like mine, come with 85mph speedo's, when you switch to the 140mph gauge faces you need to have the speedo recalibrated. If the 23 tooth gear is weak, I'd just get the 21 tooth, and then have the speedo recalibrated.

03-14-2001, 04:13 PM	#4
stng87 Registered Member Join Date: Sep 2000 Location: southern california Posts: 329	thanks quin and unit, any idea how much they charge to recalibrate and who does it?

03-14-2001, 04:45 PM	#5
slider Registered Member Join Date: Mar 2001 Location: San Diego, CA, USA Posts: 86	stng87, I have a question for you.. how are those 4:10 gears? do you have an auto tranny or 5spd? i have been thinking about getting 4:10 gears for my 87GT 5spd

03-14-2001, 08:35 PM	#6
stng87 Registered Member Join Date: Sep 2000 Location: southern california Posts: 329	i love my 4.10's, wouldnt trade them well maybe for 4.30's but probably not. I have a recently built aod. I was concerned about my gas milage as i am a pussy about losing too much of it, but I cant even see any effect on the gas milage. But in performance, thats a huge difference, even going from the 3.73's. In my experience, 373's are plenty in a 5 speed but I still think that 4.10's feel much better. Youll love it either way you go. Care about gas milage=3.73's dont=5.34's no no just joking. 4.10's Hey anyone running 5.34's is that even a ford gear?