OK, so this might be a stupid question, but do you 4spd guys use 4th gear at the track? (1/4 mile) I've never run this car at the track (no roll bar). I'm looking at the two Passon overdrive transmissions (4spd & 5spd). I'm leaning towards the 4spd version (really a 3spd with O/D in the 4th gear location), but I don't want to give up my 4th gear if I need it since I'm still going back & forth about putting in a roll bar. My car is 99% street driven with 3.91's and 26" tall tires so it's SCREAMING at 70mph and I need to do something about it.

You need to be in whatever your 1:1 gear is, at max RPM at the stripe.

Yes. I definitely use 4th at the stripe with my current 4 speed now and when I was racing with the tko 5 speed. Me personally, I would get the overdrive passon and change out the rear gears to 4.10 or 4.30s. Race up to 4th (1:1). And cruise on the hwy in 5th. I problem. I have 4.30 and in 5th with the tko (.64) at about 65-70 it is at around 2,200 rpm. Only problem is the tko didn't last at track broken 3rd gear 2x. But my car is pretty heavy at over 3900 lbs and with slicks. Many guys race it in lighter cars and/or without true slicks and never break it. Passion is supposed to be pretty beefy from what I read

Good luck

I get into 4th gear before the 1/8th mile.

Good luck on the Passon 5 speed. Some people have been waiting 5 years for one.

You might get lucky and get the passon 5-speed in the next 10 years. I'd been on the list since the very beginning and still Nada. I know it's nice when you already have all of the 4 speed stuff but I got tired of waiting. I've got a T-56 Magnum kit here at the house from SST waiting for the install in .63 and running 3.91 gears. If you went above the 4.10 range I'd probably get a .50 gear. Yeah I got to do a little mod to the tunnel but it will b worth it. Good luck in what direction you decide to go.

I hit fourth just before the 1/8 mile mark, too. You don't want the 4 speed OD. A 5 speed OD would be your best bet for street and strip. A Passon 5 speed would be great, if they are available to you. I don't know anything about your combo to determine if a T-5 would work for you.

If you put in the Passon 4 speed OD, you will only use 1, 2 and 3 at the track. For best et, you would drop the rear gear down to a 4.10 or a 4.56, depending on your trap MPH and the rpm capability of your motor.
On the highway with 4.10 gears, and the trans in overdrive, the motor will be turning 2950 rpm at 70 mph, not too bad. The torky 440 will love eating up the wide gear spreads of that trans on the street. But it will hurt your ET a bit compared to at true 4 speed.

This is just a matter of math.. if you use 4th
gear.. 1.1 now you need to know your max rpm
that you want to turn..and now you need to know
the final gear ratio.. with these numbers you
will know what rpm you cross the line at.. if
your tach is correct..plus you need to know the
true tire diameter...just simple math

What do you call screaming? I used to run 4.88's on the street for years. Drove it to work every day except in the winter months. If I recall the mopar overdrive had a real small output shaft that didn't take much to twist off. As Mr. P Body said , you base your gear and tires to max RPM's at the stripe. And also I'm also in 4th before the 1/8. If you want both worlds, get a Gear Vendor set up. Most of the HOT DOG Drag Week guys run it.

I agree with 3.91s and its screaming.My 65 with 91s and 28 inch tire falls down on RPM in 4th in the 1/4.When i ran the 88s it was great.I do shift at 6800 though and my 440 still puls there.Ill go 4.30s next.Rocky

[quote=JERICOGTX]I get into 4th gear before the 1/8th mile.

Yep, I'm in 4th before the 8th also. Shift at 6200 rpm and go thru the stripes at 6300 rpm. 4.56's with a 29" tall tire, stock 18 spline A833 trans.

When I used to race a 4 speed 340 Dart years ago of course I was in fourth by the end of the 1/4. About like 68Lar said I would be pulling fourth at about the 1/8 mile. This was in the late 70's and early 80's as you did not see all the 5 and 6 speeds back then. But you want the car geared to use all 4 gears for drag racing to take advantage of the faster rpm climb in each gear. At least back then you did before we had all these strokers and 5 & 6 speed trans. You can of course gear your car different if its a street/strip car and uses a 5 or 6 speed. Ron

Makes sense. But I wonder how much ET is saved by not having to shift a third time Even Ronnie Sox took a finite amount of time to complete a shift...

Makes sense. But I wonder how much ET is saved by not having to shift a third time work Even Ronnie Sox took a finite amount of time to complete a shift...

Within reason, the more gears, the longer the engine stays within its power curve. With only 2 shifts/3 speed setup, you will lose too much power and the car will probably go slower. Unless you are a real bad driver, or something is out of whack with your clutch setup or transmission, you don't lose an outrageous amount of time during the shift. Lug ringing or faceplating your gears will help that time frame also.

If your loosing time shifting you need to either modify the way you shift, or change to a automatic. Most people think my car has a automatic transmission and it isn't because it's slipping between shifts.

I had a 1970 Cuda hemi 4 speed car I raced for a while in NHRA stock, it had 4.10 in the Dana 60 with the 18 spline NP833. I ran a set of M&H 28x9x15 slicks on it, I would shift it into high gear around the 1100 ft. area of the track at 6000 RPM according to that tach, it was off around a 1000 RPM I found out later
I had the gears changed to 4.89 and later t0 5.13 to get the finish line RPM up to where I would shift
I should have left the 4.10 gears in it and change the transmission gear ratios first looking back now