Overdrive tranny in an A-body
You'll have I think its a .78 overdrive instead of a .69 like the A500.
FYI to all;
The thing about the GVod is you can use it as a splitter.
You can use the combo as a regular 3+1 most of the time. But,using it with a 904, you get very close ratios of;
2.45-
1.91-1.45-
1.13-1.00-
.78 od,and splits of
.78-.76-.78 skipping 1.00-.69od
So if you use it as a 5 speed, and with 3.73s;
your street starter is 9.14, and you cruise at 65=2350 with 27s.
Because the ratios are so tight you can run a really tight LSAcam, that is normally reserved for a manual trans car. This is ideal for a hi-torque SBM, meaning you can run less cam, and with the additional low rpm torque, that makes the 9.14 starter gear seem bigger than it actually is, which speaks to not needing a whole lotta stall, which means you can try the factory convertor (found money).
The 3.73s will get you 60@5300/zeroslip; figure up to 5750@8% slip; see there's your
[email protected] cam. Maybe even a
[email protected]
With the tight ratios, that engine is gonna be sitting on the fattest part of the power curve, for the longest period of time, and the 228* cam is gonna give ET results like a bigger cam would with your wide ratio A998/999.
A KD at 32mph, will kick the rpm from 2150 in second to 3630zeroslip; figure 3900 at WOT, in first gear; just past the torque peak.
So in the end;
with the smaller cam (and 3.73s)
You get
the 9.14 starter,
the 65=2350,
the 5750rpm@60mph in 2-od,
and the kick-in-the-azz blast off at 32mph.
Also; If you take advantage of the tight splits and order your cam on say a 105LSA, Then you also get
the fat SBM torque curve,
the ~1250rpm powerband requirement,
the power bulge over the top,
the increased efficiency at low-rpm which leads to higher fuel economy under all circumstances, and
the increased power extraction at cruise rpm with a further decrease in fuel consumption.
This set-up would be ideal for a hi-compression 318 to beat up on bigger engines, without having to run the big rear gears or the big for a 318, cam. This is not to say it wouldn't be even better with a 360.
It also works with the A999 ratios
2.74-
2.14-1.54-
1.20-1.00-.
78od. splits of
.78-.72-.78-.83-.78
shifting; 2.74-1.54-1.20-.78od your split into od would be .65 with a tight 2-3 split.( which you will grow to love)
The tight .83 split from 2nd to 2-od could come in handy in the Eighth. You can still run the 3.73s with 10.22 starter gear; but with 3.91s, 5300 =86 mph, just about perfect for an HO318. And 65=2460/zeroslip. A 360 would probably pull the 3.73s just fine in the Eighth, looking for 90mph@5300.
And best of all, it bolts right onto the back in minutes, after a couple of trial-fits and hammer-blows to the floorpan in key places. I used the 73-up spool mount with a poly bushing, so I also had to drop the crossmember about 1/4 inch.
Yeah it's pricey; but it turned my combo into an animal. Course I bought mine when they were ~$2300,lol. Plus doing the driveshaft twice, cuz it promptly blew the 7260 rear U-joint to smithereens. So I installed a 1350 there to match the front.
So, I'm just saying;
there is a whole lot more to a GVod, than just the .78; if you engineer your combo to take advantage of it.
now,lol, if you combine this with a tight-lash, fast-rate of lift,solid-lifter cam, one size bigger,in a 360 with 180psi cranking pressure, look out world!.