Hey, this is my first post here, and I have some questions. I have a 2WD 1990 F250 with the EFI 300-6. It has just over 230,000 on it but it runs fairly well.

I have a voltage gauge that's jumping around a lot when the motors idling. I am guessing that it's a diode in the alternator that's gone faulty?? I recently installed a fairly demanding stereo system so I guess the alternator needs upgrading.

I am looking to replace my worn out stock exhaust with something better. I would like some suggestions. I have heard a lot of good thingss about Flowmaster mufflers..can anyone ellaborate from personal experience with exhaust products they have or are using on an inline 6.

I am also wanting to change to an MSD ignition. Is this a good idea for some power improvement? And which model would suit a hard working truck?

When I am sitting in idle the truck's idle sometimes hunts up and down. I have been told this could be a vaccum problem or an o2 sensor. Is this true? Could it be something else?

I have a small oil leak that seems to leak more when the front end of the truck is downhill. Is it safe to asume this could be my front seal? When parked on a hill with the front end up the leak is noticably less.

My truck has a basic 4.10 rear end diff, I would like to change to a limited slip 4.10 rear end. Is this very costly?

Thanks in advance
John

 

Hey, this is my first post here, and I have some questions. I have a 2WD 1990 F250 with the EFI 300-6. It has just over 230,000 on it but it runs fairly well.

I have a voltage gauge that's jumping around a lot when the motors idling. I am guessing that it's a diode in the alternator that's gone faulty?? I recently installed a fairly demanding stereo system so I guess the alternator needs upgrading.

Definitely electrical related.

I am looking to replace my worn out stock exhaust with something better. I would like some suggestions. I have heard a lot of good thingss about Flowmaster mufflers..can anyone ellaborate from personal experience with exhaust products they have or are using on an inline 6.

What sound are you looking for, rasp of glasspacks or something more mellow? This is a common topic, a quick search would net you many more replies to consider, than you may receive from this thread alone, also a few soundclips here and there.

I am also wanting to change to an MSD ignition. Is this a good idea for some power improvement? And which model would suit a hard working truck?

Not on an efi truck, maybe if you introduce forced induction of some sort but not on a mild naturally aspirated engine. An immediate thread to back this up, look under your thread for one titled "Miss under load and msd ignition stuff". Keep your money.

When I am sitting in idle the truck's idle sometimes hunts up and down. I have been told this could be a vaccum problem or an o2 sensor. Is this true? Could it be something else?

Could be many things, go to your local autozone, ask them to pull your codes, they will do so for free, whatever they give you, post it here.

I have a small oil leak that seems to leak more when the front end of the truck is downhill. Is it safe to asume this could be my front seal? When parked on a hill with the front end up the leak is noticably less.

Peek under your old truck and see.

My truck has a basic 4.10 rear end diff, I would like to change to a limited slip 4.10 rear end. Is this very costly?

By basic do you mean open? Look in the door jam, you will see a white sticker, now look for the term axle code, you should see a two digit number, write that number down, then at the top of your ford-trucks page you will see Articles/Specs, click it and search for axle codes. Another option, look on the axle, you should see a tag hanging off one of the bolts on the axle cover, write all the numbers/letters down and post what you find in the clutch transmission, differential, axle and transfer case section on this site. If it happens to be an open rear, expect to pay $300+ just for the differential, not labor to make it a posi, its something a home mechanic can do.