[89bulletlx]

I have a 89 mustang lx 5.0ho t-5 with a 3.73gear and my dash cluster say iam runing 4000 rpms at 75 but but sports tac says 2000 - 2200 and its going trough the msd box my ? is what one sounds right i think the sports tech is i thing the cluster in it is out of a 4 banger but my speed o work right even tho it a 85mph one vs the 140mph that i thoght was used in the stock cars but i could be wrong plus i should have the 140mph where can i get the gear for the speed o cable or do i have to o yea my tire size is 245/50/16 if it matters

[mustanghelper]

i have a t5 with 3.73 gears, and at 2000 rmp in 4th gear im going 40 mph.

[5SpeedGT]

Your sport tach is right on. Because your factory cluster is from a 4 banger, the tach will read twice as high. The rest of the gauges and the speedo will read properly though. Did you get the proper speedo gear for the tranny? If not, that WILL throe the speedo off. If tyhe T5 is factory, it should have a 7 tooth drive gear, so you would need the red 21 tooth driven gear for the speedometer cable.

[89bulletlx]

Originally Posted by 5SpeedGT

Your sport tach is right on. Because your factory cluster is from a 4 banger, the tach will read twice as high. The rest of the gauges and the speedo will read properly though. Did you get the proper speedo gear for the tranny? If not, that WILL throe the speedo off. If tyhe T5 is factory, it should have a 7 tooth drive gear, so you would need the red 21 tooth driven gear for the speedometer cable.

Thanks a lote thats what i thoght i want to put 140mph cluster in it do you know what gear i would need or where to get one

[5SpeedGT]

The cluster itself has no effect on the gear. Only the rear gears and the speedo drive gear on the tranny affect that.

[Young_Buck]

When I had my 3.73s in my car I used a 23-tooth speedometer gear. Worked just fine.

-YB

[5SpeedGT]

I believe it was right around '90-'91 that they switched to an 8 tooth drive gear, so the 23 tooth would be right for that.