brewersperformance?
I know this thread old, but what cam are you running with the 4spd?
I have run three cams.
1) the 292/292/108 Mopar = 249/
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2) the 270/276/110 Hughes= 223/
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3) the 276/286/110 Hughes =230/
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The cylinder pressures for all three were maintained at close to 180 or more psi, by varying the gaskets, the deck-heights, and/or the rings; for use with the aluminum Edelbrock heads.
I ran the 223* cam briefly at nearly 200 psi, and this engine had enough balls to run the super-wide ratio A833od box, and spun brand new 275/50-15 BFG T/As, to past the speed limit, and broke them loose at 50/55 with no tricks.
>That iteration is still my all-time favorite combo. It had so much bottom end that I eventually gave some up by retarding the cam , to move the power-band a lil higher, and shifted it at up to 7200, with good results.
>I tried all kinds of things with this cam, including;
- every period four-speed that Mopar makes, and
- every rear gear from 2.76>3.91s, except 3.73s, and
- added GearVendor's overdrive, then tried almost everything from 4.10s>5.38s.
>What I discovered was that no matter what combination of gears that I tried, it always came back to;
1) having the gear in the right place from 30>60mph
2) a starter of no more than about 11/1
3) more than five gears was not required
4) this 223* cam, if I could meet it's needs for ignition timing, could make phenomenal fuel economy, the slower it idled down the hiway. In one test, it was geared the equivalent of having a 1.97 final-drive, 65=1590rpm.
In the end, I went back to the Commando box, Plus the GVod, often used as a Splitter; and either 3.23s or 3.55s. IMO the 3.55s combo is killer. and I usually split First and/or Second.
The Roadgears with the Commando/3.55s are;
10.97-
8.56-6.82-
5.32/-4.97-
3.88-3.55-
2.77, GV in red.
That 6.82 gear will get me 65mph@5500. From there I shift straight to 4th-over.
That 5.32 gear will get me; 83@5500/ 91@6000, and (with the 230* cam),
she goes 93@6100 in the Eighth-mile; having pulled the stick just once, and twice on the electric fast-as-lightning GV shift.(no ECM); this is FOUR ratios in the Eighth, with splits of .78-.80-.78 .............. the autos got nothing on me, lol.
Getting back to the A833overdrive box.
To get that magic 5.32ish ratio will require 4.10s, and so the Roadgears are;
12.67-9.88-6.85-5.34-4.10-3.29-2.36, GV in red again. and
65=1910rpm
I really liked this combo;
with 4.10s it has a great parade gear that allows 550rpm= ~3.5mph.
Because of the deep-low, I tried starting in First over; but the GV will not hold enough pressure thru a stoplight. But it will, usually, at a stop sign.
But I kept forgetting not to slam it into fourth, which instantly rips all the teeth off that tiny od gear. :( and when those teeth find their way into other gears, the end result is ugly.
So after the third trans, I abandoned it. Altho, after the last blow up, I cleaned the box out and ran it without the tiny od gear in it, losing the 2.36 ratio. Well. I left the gear in there but turned all the teeth off it. Then I switched to 3.55s, duh, and the Roadgears were;
10.97-8.56-5.93-4.62-3.55-2.77; again GV in red.... 6 gears, but lost the crawler gear. So I retuned, to idle in gear at 500, and got 3.66mph. Not bad. Except for one thing; the main box splits are pretty wide and splitting ALL-THE-TIME ........... gets old. I would have liked to try 3.73s for a better Second gear (6.22), but by this time, I was done with that box. Since that last switch in 2004, the Commando/GV/3.55s have stayed, except for a short stretch with 3.23s , and an even shorter stretch with 2.76s.
Also, the 230*cam went in in 2004, after the 223* cam dropped lobes. Cylinder pressure changed to a tic under 180psi.
Since that time, I have sold off everything bigger than the 3.55s except for one set of 4.88s.
Oh, BTW
Many guys complain about the modest .78 GVod ratio.
Well, typically, I shift at 2800 cuz that's when my 367 starts to growl real nice at Part Throttle; and I shift into overdrive after Third gear, and then a final shift into Fourth still in od. Here's how that looks on paper, with the Commando/3.55s
10.97(1st)-6.83(2nd)-4.97(3rd)-3.88(3od)-2.77(4od); GV in red again. The splits are .62-.73-.78-.71; as you can see, this is exactly like running 3.88s and a .71 overdrive.
From 2800, the rpm drops at each shift, are to;
1736-2044-2184-1988 (try pulling that with a lo-pressure iron-headed any-stock-stroke SBM)
enough said.