Ok guys i was wondering if ya'll could give me some ideas of places to look for a 4000 RPM tach. I really don't want to buy a 8000 RPM cause I won't use half of it with a 300. I haven't been able to find one that is decent priced and i won't have to take out a small loan to buy. I also heard a rumor some where that you could use the dual exahaust manifolds off of a fuel injected 300 and they would give me some more HP. I really want to do this if it will give me some HP because i could probably go to a local junkyard and pick them up for a good price. Please help i'm 15 and tryin to get my truck goin good with a limited budget.

80' F-150 Ranger extended cab lwb (this sucker is long)
limited slip rearend
300 6
Cherry Bomb
4" air cleaner

 

Yeah, over the log exahsut manifold that came with your engine, those split exhaust manifolds flow like a header until about 3500rpm. I've found a decent tach in Jegs, it's a 6000RPM one that is about $60 I believe, I may get but at the moment I'm trying to find a truck that had the factory tach.

 

For a good tach for a mild 300, go find yourself the instrument cluster out of a gas powered 80-98 F600-900, the 429 powered one I was working on today had a 4500 RPM factory tach, instead of the standard half ton 6000 RPM piece. If your truck has gactory temp and oil pressure guages instead of idiot lights, it should be a direct bolt/plug in, at least the half ton 6000 RPM piece was in my 82.
Evan MacDonald
1982 F100 SWB
300 HD: Cliffy 290H, 9.1:1 compression, forged everything, ARP'd bottom end/Hedman hedder/dual 2½" exhaust
NP 435/2.75 geared 9"
1986 F150 HD, 300 HD/needs a NP 435/4.10 geared 8.8
70,000 miles
1984 F150 XLT Lariat parts donor, 351W/C6/9" LOADED to the hilt, 201,000 miles
1980 F100 Custom, 300/Np 435/2.75, 58,000 miles

 

See my $65 4000 rpm tach from J.C. Whitney in post 3 and mounting location in post 11 at this thread: https://www.ford-trucks.com/dcforum/DCForumID9/966.html
I got this one two years ago and am very happy with it, though its lighting is not that great. I mounted it in the right side of the dash by cutting a hole where the electronic 4wd controls would be. I have the JEGs 6K tach in my motorhome and, while it is very nice, wish I had gotten another of the 4K tachs as the motorhome only goes up to 4100 rpm. If I had it to do over, I think I'd put the tach in my pickup on the top of the dash where it is really easy to see (like I did with the motorhome).

You can also get the Whitney 4K tach (which is a Datcon) or other brands like Stewart Warner (I think) in whatever max RPM you want (e.g., 3K, 4K, 5K, etc) and in various sizes at Fuel Systems in Wisconsin (262-781-4353).

Oh yeah, somewhere I saw on the web that the Datcon is OEM spec. Anyway, that may be why it comes with no wireing harness, but only terminals on the back and you build your own wiring harness (a simple job though). Also has an adjustment screw in back for calibration (don't turn it though, as factory set) and instructions for about 12 different ways to hook up depending on how your vehicle is set up (I think much of these are for tach applications on equipment etc.

INLINE SIX POWER!
300 Cubic Inches of Low RPM Truck Torque! And twin-I-beams too!
"Drive a stick young man! There'll be time for automatics when you're old and unable."