[hatzie]

Originally Posted by esbstuff

3500's make good boat anchors. Use the 4500 and it will last almost forever.

I've killed 5th on a 4500. I installed a 3500 in a buddys truck that's run 100K and still going.

The 3500 is a good transmission if you stay within its limitations. Don't exceed 300 ft lbs or tow extremely heavy loads and it'll be just fine. The NV3500 is relatively light, fairly easy to find, and cheap. It's a geared for fuel economy... 4 useable forward gears with OD (5th).

The NV4500 is difficult to find, big $, and heavier than a dead horse. It's not exactly an economy transmission being a 3 speed with LOW (1st) and OD (5th).
I've done this swap on my '76. If I had it to do again I'd use a Gear Vendors OD on an SM465. I like my NV4500 and it gets me bragging points but from a purely functional point of view the SM465 with an OD box is way better.

1. When you factor in the transmission cost and clutch conversion time (almost a month for me and I'm billed out at $110/hr) & money the cost is pretty close to the same.
2. The SM465 is EXTREMELY difficult to kill.
3. The SM465 is way cheaper sometimes even free.
4. The SM465 bolts right up with stock parts and no drama.
5. The SM465 mates with the NP203, NP205, NP208, & RH drop NP241 with stock parts and no drama. The NP208 & NP241 will bolt up to the NV4500. The NP205 OTOH is a difficult expensive dance and if you want to use the NP203 low range case for a low range doubler be prepared to shell out even more.
6. The SM465 has the same extremely low 1st (6.55:1) as the rare 1993 NV4500.
7. The Gear Vendors OD matches the 0.73:1 NV4500 OD ratio and you can split 2nd & 3rd gears if you wish.
8. Best of all... you can tow in OD without shearing the 5th gear to mainshaft splines (that killed my 1st NV4500). With the NV4500 you are stuck towing in 4th.