I’m building my small block with the goal of 12 second 1/4 miles (350-370 Hp) I have found 4.10 gears and a locker. Should I spend my money on a heavier duty rear axle assembly?

 

As mentioned in your other thread, a true locker is going to play havoc with that 8.2 rear.

 

What is the weak link? axles, carrier, or gears? The unit I found for 8.2 is available through summit racing, https://www.summitracing.com/parts/PWT-92-0782-2801 and it looks like a locker and fits in stock carrier. Richmond also makes a 4.10 gearset. Don’t find axles anywhere.

 

I've had a similar set up in my car for just over a year now in a type O with 3:08 gears. Very easy to install and it works well, but to some the ratcheting noise is annoying. I did not know much about these and went through a member (monzaz) on this site that is really familiar with rear ends and parts. His prices including shipping are very competitive. Jim is a great guy, link below.
ClassicOldsmobile.com - View Profile: monzaz

This is my install project in a 67 Cutlass combined with replacing the rear suspension.
This winters project, rear suspension and locker install - ClassicOldsmobile.com

 

I know it’s not exactly the same but they are very close. My dad ran his factory 8.2 in his 65 nova drag racing since the 90’s( on and off), gears, mini spool, moser axles. Tons of low 11’s some 10’s and he just pulled it a few years ago when he decided to back half the car. Sure it wasn’t happy( axles twisted a spline or two) but no failures. I ran the 8.2 with Chevy guts( stock axles) in my 66 olds, not much track time but I wasn’t nice to it and I had zero failures.

 

I broke a no slip on a 7.5" rear at the track but the spider gears on that rear are small. Some claim the 8.2 is good to 500 hp but slicks and power find the weak spots. Heck, mine found it with barely any power😁.

 

Not sure the two are the same, but I've run a Chevy 8.2 into the high 8s @ 3100 pounds with a power adder in the 80s, never broke it, but were careful with it, locked carrier. I also have a 80s Camaro with a 7.5 custom built that runs 10.0s NA and its been reliable, but does have nice parts inside.

 

If you're planning on running at the track I would do a lot of research first on the 8.2 . Brian Trick is on facebook he builds a lot of diffs for the Olds and Buick comunity.
He used to post Classic Oldsmobile and Real Olds power not sure if he still does. You might want to talk to the https://www.moserengineering.com/

 

Bolt in axles are a plus, aftermarket axles are another plus.

 

My '67 442 had an 8.2 axle and I had a deal on a Detroit Locker and went for it! Granted, the '67 at 3500 was probably a little heavier than your '64. I had been routinely running low 12s at the time with a mild built 400. First run with the locker, the right rear axle broke! I put a 1968 "O" type axle under it and have not had any problems since; that is unless you call ripping out the welds on the cross member a problem!

 

Just carry a shovel and bucket in the trunk of the car to pick up the pieces. It's all good.

 

8 second, 3400 pounds, 9 inch tire, NA 10 bolt