I had great luck with 8.750" but a Dana 60 is the way to go,
especially in a heavier car like a B-Body...
IMO if you're starting from scratch on the beginning of a build
spend the $3000 on a Dana-60 or
even better yet a Strange S-60, bolt in if need be...
Been there done that...
By the time you build a 8.750" to handle any real power over 600hp
you could have got a Dana 60 in relatively stock form that'd last,
pretty damn well...
I did have an 8.750" {Mopar 8.750" 742 center section, ring & pinion anyway}
in an altered 27 T Brogie style {Fiberglass body}
Raced in Goodguys events & SCTA or other Nostalgia stuff...
I had a 526ci alum. Milodon Mastodon Hemi/Blown Inj./Alky
1500+hp in front of it & a Clutchflite
{6.69 @ 217 best, it was a tire fryer, run in hi-6's all day @ 190+},
it lived exteremly well, I also refreshed as needed/frequently...
Albeit; it had all hi-$$$ Lenco pieces, softer style pro-gears
trussed, full floater 60 style ends, billet caps,
35 spline riffle drilled axles & spool {it also cost over $3500 in 1990's $$$'s}
the Car was 1880# chromoly tube chassis & with me
add another 225#'s at the time in it {my skinny days}
2200#'s with fuel, 3-20/firesuit/helmet, fire extinguishers etc.
the alum. Blown Hemi engine was the bulk of all the weight ...
I was going after extreme light weight,
it was the strongest lightest at that time...
It was also "Not" some 3700# full bodied car...
I don't think they even build that stuff anymore,
you could build one, from scratch Like I did,
but it's not really cost effective, when a S-60
or pretty much stocker Dana-60 would do the job very well,
at a 500-600hp {max} at the rear wheels level...
IMO when you start getting above that level RWHP,
even with a Dana-60, it needs race specific parts, for the abuse...
I did have a 8.750 with a "alum 742 MP center-section"
35 spline MW axles, green bearings & trussed, with an Eaton diff.
in my last ol' silver 68 RR went best of 8.58 @ 156 3520#'s on n2o...
9.77 @ 135 best N/A both on MT Drag Radials/CalTracs...
I never broke it, drove 12,000+ street miles & had at min 100+ passes
on the 1/4 mile testing & tuning, wasn't legal for how fast it was,
only had a roll-bar...
It's still driving around south Sacramento Co. {last he said 25,000 miles}
the guy I sold it to still runs it today, same combo freshened up,
minus the n2o & it still dips down into & runs 9.90's N/A
every once in a while & it's still street driven too...
It also cost;
$1000+ {IIRC ball park prices 2002/3-ish} for the MP alum. center section,
$500+ for the Eaton diff,
$400+ for the axles, $400-$500+ for the bearings, spacer & gears,
$200+ for misc. stuff, ends, axle bearing & the home built truss etc.
& I did all the narrowing, no labor cost, all sweat equity...
That's $2500-$2600+ with no labor cost,
you can get a nice Dana-60 for close to that, not worry...
With all of the added labor costs, if you can't do it yourself,
it'd be more than a nice "starter" Dana-60 or S-60...
Good luck the 8.750"
IMO they are also far tougher, than many people give it credit,
if set up & done properly, with quality parts/pieces...
