okay so im not sure year hp or anything of my 350 has a t5 tranny and I noticed the rpms go by the 100x okay it idles at 150(thats normal right) and I believe that the numbers turn red at around 5 at stop at 7 but in my personall opinion it doesnt sound like its time to **** until 7 if Im really getting on it a lil help here
ps can some show me where to find the engine id at with picture preferable

 

yeah, mine idles at 1400-1500, seems to be as low as mine can go without dying. as far as the rpm's.. same as well. starts at 5, ends at 7.

 

theres a block casting number at the back left of the motor where it meets the bellhousing.

 

I'm guessing, this is what the factory "tach" says?

That pointer-wavy thing in your dash isn't really a "tach"; it just looks like one. Consider it a tach-shaped "sport trim" object. They are notoriously inaccurate from the factory, since all they're supposed to do, is go up and down in rough accordance with engine RPM to convery an "image" to the driver of "sporty" appearance, but aren't designed to be "test equipment" grade.

Sounds like yours has failed in the mode they ordinarily do, which is, to read WAY high. Sounds like yours is reading at least double the actual engine RPM. Fairly typical. I have a pile of em; I have one that was only about 5% high last time I checked it against a CALIBRATED frequencey counter, and I think I have one (haven't thrown it away yet) that reads 3 times actual.

Normal idle, as per the sticker on your radiator core support, is something in the range of 650 RPM. Since your motor isn't factory, "normal" could be almost anything, but isn't likely to be 1500 RPM.

You may also have the further complication of a 6-cyl tach hooked to a V8 engine, which would also cause it to read high by a factor of 8/6 (1.33333 times what it should), even if it was dead-on accurate.

 

so I need to go buy an aftermarket rpm gauge, and as for my speedometer I assume isn't plugged up because it doesn't work, its it a pain in the *** to plug it in and will it work correctly if I get it plugged in

 

Couldn't say about "need"; lots of cars seem to get by just fine without a tach. But yes, you either need to replace it, or fix the existing one. There's a write-up somewhere on this site about that.

Yes plugging the speedo cable in would increase its chances of working. I have no clue whether anything else is wrong with yours or not. Probably not but who knows.

 

A true 1500 rpm idle at operating temp would seem really high to you, so your tach is off as mentioned. A 'normal' idle would be 600 - 1000 depending on the car. Older basic emission sniffer tests wouldn't 'sniff' if the idle was above 1100, since at that rpm most emissions would be less anyway - they would fail the car until the idle was lower.

 

so can anyone tell me how to go about getting my speedo working assuming it just needs to be plugged in

 

Plug it in

See what happens

Go from there

Not rocket science d00d

 

lol how do I do that sorry new to all this like is it by the tranny do I need to go indash what?

 

Starts at the trans, ends at the dash; might go through the cruise along the way, depending on what kind of car you have and what year and whether it even has cruise

 

You dont say what year the car is. At some point(89 IIRC), the speedo drive changed from cable to electronic with a VSS installed in the trans. Assuming it's an early version, most likely, since the engine has been replaced, the cable is disconnected from the transmission.

 

yes it is a 84 is it so simple a caveman could do it Im really new to cars

 

Actually it's even simpler than that... it's so simple, I can do it.

You can handle it.

 

well what do i do where can I find the plugs I not sure what to do