How much you guys think a 89 Peterbilt 379 is worth?

I agree. If he was hauling steel he was probably heavy and that 11.1 has probably been put through its' paces.

 

Anyway, do yourself a favor. Don't buy it. Take the 12k and use it to buy a truck that's 15 years newer. You'll be better off in the long run.

 

And to give you some idea. That 15 speed is more or less a 10speed with a power take off. You split the first 5 in the low side. It's for really heavy loads. Normal loads you'll shift it as a 10speed.

 

I delivered with another truck today. It was an '88 379 flat top from Baltimore. MD with a 13 + 3406b. Basically the same truck as mine. The driver said his boss was selling it and he was asking $15,000. Rebuilt engine, rears & trans. The interior is pretty good shape and the headliner was mint. Needs paint bad. I got the impression the price was negotiable. Based on this, I would say the OP's is overpriced. Not a beauty queen as she sits but with the 13 and the 425 B model, she has good bones.

 

i'd be a little worried about the engine swap. and don't say that was all that was swapped. cuz the wiring harness and ecm aren't the same between the 2 motors.

he went from a cat to a detroit. that's like swapping out a ford for a chevy motor. there's going to be a lot more work involved then just simply swapping motors.

if the truck were original, 12k would be all right. but it's not. even 5k is too steep. your GOING to have issues. and getting it repaired is going to be a seperate set of issues along with the issues.