Need help on a tach question: I have a 1990 F-150 with the 300 strait 6, the instrument cluster has the tach that goes to 6000 RPM. I want to change it out with the diesel tach that goes to 4000 RPM. I was going to find one from a diesel 87-91 pickup and just take the tach out and put it in my cluster. Would this work? Any adivce appreciated. Thanks.

 

Whats wrong with the tach you have? My 95 I-6 revs to 5500 so why would you want to take it out?

 

If anything I'd buy an aftermarket tach, much less work and yeah, 4 grand is a little low for a strait six.........5 would be alright cus ive never taken mine over 4500 cause i dont like the way the truck sounds and shakes lol

 

I forgot to mention that the tach I currently have is dead. Would I just be able to remove the dead 6000rpm one and put the 4000rpm one in its place?

Thanks

 

Diesels don't have spark plugs, but are compression ignition. Therefore, I am not sure how easy it would be to hook up a tach made for a diesel to a gasoline engine. For my 300 I6 I bought a Datcon 0-4000 rpm tach. I have had three 300s and never took one over 4000. In fact, I rarely go over 3500. The hp peak is 3400. Unless modified, these engines are supposed to run out of breath around 4000+.

INLINE SIX POWER!
300 Cubic Inches of Low RPM Truck Torque! And twin-I-beams too!

 

hello, i use a summet tach. it is up to 8000rpm. but i redline at 2500-3000rpm. its a stock 300i w/ rebuilt 3-sp conversion

 

what kind of 3spd conversion did you do?

 

I bought my 1995 f150 4.9 a few months ago, and the way it pulls, have no need to ever go over 2500-3000rpm. i just installed a Sunpro tach and hung it inverted using the left driver visor mount as its base mount

 

I have a 1995 f150 with the 4.9 300 I-6 and I've been wondering, how do I hook up a tach? I got a tach from my buddy and he says it should work but he never told me how to install it, and he's since moved away and we're out of contact. any help would be great. Oh! one more question, since I have the 379 rear what would the apx rpm of doing 65 Mph with no load? if I can find that out I can calibrate the new tach when installed.

 

If you poke around the Sun (tach company) website you should be able to find instructions for tach hookup. Expect yours likely is similar. Basically four wires: power, light, ground, and ignition signal. Power and lights you want on switched circuits (I just flatten the bared wires and jamb the fuze in on top of them (I know, this is not professional, but it works). Just make sure you are on the cold side of the fuze so your circuit is fuzed. Not sure where to hook up the ignition signal, but somewhere in the vicinity of the coil/distrinbutor--usually.

INLINE SIX POWER!
300 Cubic Inches of Low RPM Truck Torque! And twin-I-beams too!

 

G'day from Oz. I have a 1971 with a 300 E.F.I. transplant. The ignition system is original from 1988. Can you tell me where to hook up my tacho? There are 2 wires (other than light) to connect. gp.