right, the 727 is the old 3 speed transmission that's been around for ever. The 46RE is what went behind the 5.9/360 gas motor stock, but is computer controlled (RE = RWD Electronic). You'd want a 46RH. It's basically a 727 with an overdrive box hanging off the end. BUT I do not know if it has a mechanical speedo/odo drive or not.

 

I did say RH.

 

I never said I could see straight. does the RH has the mechanical speedo drive?

 

I don't know. Maybe some one can answer that.

 

call PATC- http://www.transmissioncenter.net/

They seem to help alot of people with 727 -> A518/46RH swaps, and how to control the electronic clutches for the torque convertor and overdrive box.

 

Some RH's were electronic and some were not. What other choices do I have for autos? I would also consider a standard. Are standards or autos better for the drag strip?

 

for drag racing you will want the 727, not a 46 box with OD, weight wise. BUT, the 46 has it's advantage. Again, get in touch with PATC. If you race with an OD box, you have to disconnect the TCCS (which will be easy seeing as you're going computerless) and make sure the OD box stays disengaged as much as possible (again, easy with computerless). And make sure you have a huge @$$ trans cooler on it. I have the stock cooler in the radiator (lincoln fan) and a 16 pass under my bed with a 10" fan, and the intermediate temp between the 2 coolers is 180 on the highway and gets to 200 in a hurry at the strip. And I only have a V6, a V8 will put more heat in the trans/convertor.

There's 2 sides to this sword: The 46RH is 80 pounds heavier than the 727, and 60 of those pounds are internal rotating parts that take more power to turn. BUT you can take advantage of the OD in the 46RH, if you build the suspension for it.

727: 2.45, 1.45, 1.00
46RH (A-518): 2.45, 1.45, 1.00, 0.69 (AKA a 727 with OD hung off the end)

2.45 * 4.10 = 10.04
1.00 * 4.10 = 4.10
0.69 * 4.10 = 2.83

2.45 * 4.88 = 11.95
1.00 * 4.88 = 4.88
0.69 * 4.88 = 3.36

2.45 * 5.13 = 12.56
1.00 * 5.13 = 5.13
0.69 * 5.13 = 3.53

If it were me? I'd be finding me a 46RH and throwing 5.13's in the *** end. Gives you a better highway gear than the 727, with an @$$load more of launch.

I put 4.10's in my truck, strictly because I needed highway mileage. If/when it goes strictly strip, i'm doing just that- throwing the deepest effing gear I can find to fit the axle. It actually gets to a point that you have to watch your top end RPM. For my truck's setup (42RE), 5000 RPM would put me at 112 MPH with 5.13's and the .78 OD and a 30" tire.

 

This truck will still be my dd I think I forgot to mention that. What would 5.13s do to city mpg?

 

City MPG peaks around a 4.30 gear, you can go up to a 4.10 or down to a 4.56. 88 and 13's are too deep for practality as a DD. You can certainly do it, though. The OD saves quite a bit here. Just a matter of how much RPM you want to turn and how much fuel you want to burn. From 3.55 to 5.13 you're gaining 1,000 RPM to go 70 MPH and about 700 RPM to go 55.

These numbers tabulated with a 0.69 OD and 30 inch tire.

With the V8 swap and the 46RH, I think you could make it work- the 46 has an extra-deep OD (0.69) compared to the rest of the lineup's 0.78 OD, and a .69'd 5.13 is comp to a .78'd 4.56. So for you I would stick to a 4.88 if you want to burn rubber or a 4.56 if you want fuel economy. IF it was an all out race truck, again, 5.13 all the way.

RPM .................... 3.55 ............. 3.92 ................... 4.10 ................... 4.56 .................. 4.88 .................. 5.13
4000 RPM ... 145.74 MPH .......... 131.99 MPH .......... 126.19 MPH ......... 113.46 MPH ......... 106.02 MPH ......... 100.86 MPH
3500 RPM ... 127.53 MPH .......... 115.49 MPH .......... 110.42 MPH......... 99.28 MPH ......... 92.77 MPH ......... 88.25 MPH
3000 RPM ... 109.31 MPH .......... 98.99 MPH .......... 94.64 MPH......... 85.10 MPH ......... 79.52 MPH ......... 75.64 MPH
2500 RPM ... 91.09 MPH .......... 82.49 MPH .......... 78.87 MPH......... 70.91 MPH ......... 66.26 MPH ......... 63.04 MPH
2000 RPM ... 72.87 MPH .......... 65.99 MPH .......... 63.10 MPH......... 56.73 MPH ......... 53.01 MPH ......... 50.43 MPH
1500 RPM ... 54.65 MPH .......... 49.50 MPH .......... 47.32 MPH......... 42.55 MPH ......... 39.76 MPH ......... 37.82 MPH

 

Is the air bag controlled by the PCM also? I don't really need an air bag but it would be nice.