I will admit I am biased to a very low first gear and that may not be applicable to your situation. I live in Shitty City and bumper-to-bumper traffic is the norm. I like to be able to just work the clutch in and out and creep along without riding it. If you live out in the country you can probably get away with a less steep ratio. It is up to you. But at least you are researching the issue and that is the key to success. I know the Saginaw gets a bad rap but I have been using them for almost 50 years and I have never broken one. They have a stiff cast iron case and a wide range of ratios. The 3:11 version you mentioned I used behind a strong 400 with 3:23 rear gears for over 10 years. It was a perfect set up with a 10 to 1 ratio. Not a peep out of it and I was not easy on it. Not teenage stupid, but not easy by any means. In my opinion, what kills Saginaws is uncalled-for abuse, and not having the right gears out back. If you take a car with automatic rear gears, like 2:56, 2:78, even 3:08, and force them to work with a manual trans without enough first gear, you are straining the parts and something has to give. It's like riding a 10 speed bike. Do you start out in 5th gear, or first gear? Same affect. The only part I have ever seen fail was the wavy thrust washer at the rear of the main case. They make a Torrington roller bearing to upgrade that, but as I said, with the right gears, no problems. Also, oil leaks kill manual transmissions. Lots of places to leak from, no one checks the oil level. and the first thing to go is the cluster gear bearings. It is not hard to re-build a manual trans and change all the seals. Getting it out to work on- that is the hard part. EDIT: The Pontiac 400 never came with a Saginaw, but the 350 did. Same stroke, same rod length, similar torque. And a factory warranty.