I6 Swapped to sbV8 - Factory Tach?

[cairo10]

I'm finishing a swap project - AMC 258 i6 / 4.2l I6 out and 350 V8 in with a MSD HEI coil.

Is the factory tach switchable from 6 cyl to 8 cyl? Does it pull out? I tried to climb under there to unscrew back bracing and it's held in place by a plastic cup?!? The last thing I want to do is break it by pulling/twisting the wrong way.

Thanks!

 

[richardoutwest]

I don't think the factory tachs are switchable. When I got mine it was specifically for the AMC 304 . There is a brace in the back that has a screw on it and is held on to the dash to keep it from coming out. The blue plastic is part of the sealed tach itself. It may be snug but it should push out. I will try to find a pic

 

[cairo10]

Thank you Richard. I was afraid of that! I'll start looking for a replacement.

Mine doesn't have the brace in the back. It is a white plastic cup - like a spray can lid - with a slot on the bottom for the wires. I can see the blue plastic part of the tach inside. The tach housing spins at the dash and the blue housing spins too but the white exterior stays in place. I may try to slide a screwdriver in the back to pry the tach housing out.

 

[72rtchallenger]

I am pretty sure they are switchable ,,if you go and buy a factory replacement they dont ask for the engine size and every after market tach that I have bought would fit a 4 6 or 8 cyc but I cant say that I am a 100% sure,,but you can find them on ebay new or here http://www.jeep4x4center.com/tachometer-fits-cj-factory-location-5459418.html which says it fits all engine sizes

 

[richardoutwest]

72rtchallenger, the aftermarket tachs that look like OEM are yes switchable, OEM factory are engine specific. Good option but not sure on the quality. Most of the stuff out of China are, well out of China. I learned really fast on China aftermarket stuff, would rather buy used OEM and be done. Shifting boots, cowl seals ect will only get you about two years in AZ.

 

[72rtchallenger]

tks richardoutwest good to know as I wasnt completely sure,,do you know the difference ? could they be re calibrated ?

 

[richardoutwest]

not sure, thats over my head!

 

[bdpalace]

There should be a phillips screw in the center of the cup. I had to use a shorty phillips to get it out. Once you remove the screw, the tach will slide out.

 

[JCsCJ]

Like bdpalace said there is a screw holding the cup on the tach. I have the factory tach mated with sbc350 and haven't had any issues.... well at least not yet:dunno: