1957 150

ss wannabee · 08-14-2011, 10:27 AM

I would think the rear could live " beefed" for an automatic...Of course the 12-bolt would be stronger...and has a better list of parts available. But if you're "gung-ho" on "flogging" that 10-bolt...you'd have to work around some disadvantages...One is I don't think anybody made "Pro" Gears for this application EVER...so I would suggest "prepping" the available gear sets as best you can...de-burring, heat-treating, or whatever "current" metal process is suggested for stress-relieving today. Another problem with the "old" gears is ratio selection is a bit weak as they jump from 5.57 to 6.17 while the 12-bolt has 5.57/5.86/6.00, and 6.14 ratios...a better selection to "fine-tune" your combo with. Yes, the pinion is small on the 10-bolt 6.17 ring & pinion as mentioned before...a definate liability! BUT your combo might not require such a "stout" ratio depending on what you will run for tire size, trans ratio, etc....Another problem with the early rear end is I don't think anybody made a SPOOL for it although it could be "custom-made"...check out "Aubrey's " site the guy in Canada with the 409 car. I think he's running the 10-bolt in that car still....although a LOT of work to make it live. The GM "Arma-Steel" posi unit is pretty strong BUT needs help with NEW heat-treated FINE-SPLINED spider gears (for the custom axles), and other mods. Unless you have one of these NOW, they could be a bit pricey at swap meets today...I would also consider steel differential carrier "caps" (or reinforcing straps for the stock caps), larger grade-8 bolts, etc. All of these mods were pretty much "standard-issue" for racers running this rear-end back in the day...although today's horsepower levels, better tires, and better track prep should be factored in the decision...I would try and contact Aubrey...or maybe Tom's Differentials for more input on your situation....Good Luck!

08-14-2011, 10:27 AM	#13
ss wannabee Senior Member Join Date: Jun 2005 Posts: 663 Likes: 0 Liked 5 Times in 5 Posts	Re: 1957 150 I would think the rear could live " beefed" for an automatic...Of course the 12-bolt would be stronger...and has a better list of parts available. But if you're "gung-ho" on "flogging" that 10-bolt...you'd have to work around some disadvantages...One is I don't think anybody made "Pro" Gears for this application EVER...so I would suggest "prepping" the available gear sets as best you can...de-burring, heat-treating, or whatever "current" metal process is suggested for stress-relieving today. Another problem with the "old" gears is ratio selection is a bit weak as they jump from 5.57 to 6.17 while the 12-bolt has 5.57/5.86/6.00, and 6.14 ratios...a better selection to "fine-tune" your combo with. Yes, the pinion is small on the 10-bolt 6.17 ring & pinion as mentioned before...a definate liability! BUT your combo might not require such a "stout" ratio depending on what you will run for tire size, trans ratio, etc....Another problem with the early rear end is I don't think anybody made a SPOOL for it although it could be "custom-made"...check out "Aubrey's " site the guy in Canada with the 409 car. I think he's running the 10-bolt in that car still....although a LOT of work to make it live. The GM "Arma-Steel" posi unit is pretty strong BUT needs help with NEW heat-treated FINE-SPLINED spider gears (for the custom axles), and other mods. Unless you have one of these NOW, they could be a bit pricey at swap meets today...I would also consider steel differential carrier "caps" (or reinforcing straps for the stock caps), larger grade-8 bolts, etc. All of these mods were pretty much "standard-issue" for racers running this rear-end back in the day...although today's horsepower levels, better tires, and better track prep should be factored in the decision...I would try and contact Aubrey...or maybe Tom's Differentials for more input on your situation....Good Luck!