Overdrive options
I have been running the GVOD since 2004 behind my 367 in a 68 Barracuda with a stick. I have run so many different rears I have lost track of them all. And yes, even 4.86s.
The nice thing for me was rewiring it to run as a gear-splitter. With the right mainbox, this keeps my little engine on the pipe, making it trap as tho it had a lot more cam. This may not apply to your combo I just thought I'd throw that in.
It traps at 93 mph(1/8th) which would be second-over @ 6400, with 3.73s. And the starter gear is 3.73 x 3.09=11.53 which with an automatic would be like 11.53/2.45=4.70s. And the hiway gear is 3.73x.78=2.91, making 65=2350.
But I run 3.55s now.
And thinking about putting the 3.23s back in. ( which with a 727 would be like 4.07s)
I love my GVOD.
My 4.86s are for sale.......5.13s busted,3.91s busted...........4.30s sold,4.11s traded away. The 4.88s in storage, with the 3.23s,2.94s,and 2.76s..........Sheesh, I almost forgot all the crap I ever tried.