Top Speed?

What is the top speed for a 72-75 with 3.73 gears and a 304? Mine doesn't have much after left 60 MPH. I normally cruse at 60 and try to get to 65 on the highway (short distance) when going to work or visit family. It just seems like it should have more guts. Could it be the carb running lean, not enough air getting to the carb from the factory air cleaner or tired engine?

 

Should be a heck of a lot more than that. Something there is very wrong. It's a long list of "what it could be" but is this new? Or has it always been this way?

 

Linkage adjustment? Floormat under the go-pedal? Air-cleaner full of acorns? Exhaust pipe crimped?

Look around and wiggle stuff before you tear into anything.

 

Something ain't right. Can you post a youtube video and link it into a reply here?

 

My ol 75 CJ/304 would go 80 if I wanted. That thing was a hotrod. Cruise 70 no prob. Even with an OEM type Motorola carb it ran. I eventually installed TBI and it ran even better.

 

My 75 with a 258 and 3.73 would do an indicated 85-90. A few semis were playing leapfrog with me on the freeway, so I left them behind.

 

I can't say for sure because I never really took it above 55 until I replaced all the steering and suspension because it was so sketchy above that. The only things I did to the engine were a DUI distributor, new radiator, water pump, fresh air cleaner element, new wires and plugs, headers with cherry bombs and a new carb. No carpet or floor mat to get under the pedal. It's almost like it has a governor some how.

 

I'd check the linkages and their operable ranges.

 

Just curious, what is the normal range of the gas pedal from the floor and at rest? I'm wondering if mine was bent in such a way to not allow full throttle.

 

my 74 with 304, 3.73 and a 32 inch tire will top 90 if you want to hold it that long

 

Not sure if this is the best way to test it, but what happens if you roll off the line in first gear and keep accelerating without shifting? Does it top out at some unreasonably slow speed with relatively low RPMs, or will it keep accelerating to redline?

 

Watch the linkage at the carb while you cycle it as far it will go by pushing the pedal, then remove the pedal linkage and turn the carb butterfly by hand. The amount the carb opens should match.

 

I have had it over 3500 and it will keep going.

 

I will give it a shot and see what I get.

 

Quite a bit of difference! I had to prop my phone up and took a video of pumping the accelerator pedal and manually moving the butterfly by hand. There is about an inch of difference. The throttle cable bracket is different keeping the cable off to the side as well. I think there is something in the pedal where the throttle cable connects is too far forward not allowing the throttle to fully open. Does anyone have a measurement (open and closed throttle) of this part?

 

Why not simply adjust it/fix it until it will open the thottle plate fully, plus a tad?

 

I ended up adjusting the angle of the accelerator pedal (not sure if that was the correct way to adjust it) and now I get full range on the throttle plate. I hit 65 before I got onto the highway and 80 wasn't any trouble at all. Just curious as to how far from the floor the accelerator pedal should be?

 

If you can hit 80 MPH...it doesn't matter about accel pedal to floor dimension.

 

I think your right. I chickened out at 80 otherwise it would keep going.

 

Finally, I found an example of the etymology of 'mash it to the floor'