# 4 speed or 5 speed for drag racing?



## ottfive (Jul 23, 2012)

I have a 66 GTO 428 3x2 with 3.55 gear close ratio 4 speed muncie with 2.20 ratio. I am considering a trans change from 4 speed to 5 speed because of cruising and drag racing. Is the change over from 4 speed to 5 speed better for drag racing and what could I expect in et times? Thanks Jeff


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## geeteeohguy (Feb 2, 2008)

For drag racing, you'd be better off with a wide ratio Muncie M20 with your 3.55 rear gear. It has a 2.52 first gear. Close ratio boxes were used with 3.90 and steeper gears. A 5 speed with an overdrive gear is better for cruising. Not as quick to shift going down the track. It all depends on your ability to row a stick. There are some gents who can speed/power shift a Muncie so fast it'll make your head spin. I wish I was one of them. It takes big brass cajones and a huge leap of faith to pull gears with your foot to the floor and without using the clutch.


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## ottfive (Jul 23, 2012)

*4 speed or 5 speed for drag racing*

Thanks for the info., I have heard the close ratio was for 3.90 and up ratios. Not sure why previous owner used the close ratio Muncie? It is the original rear end with 3.55 gears. I only power shifted a couple times without clutch but didn't like the abuse I was putting on tranny/clutch/. It did run about .5 faster than speed shifting using the clutch. Just was wondering with 5 speed the best of 2 worlds with improved mileage and less stress on engine with lower rpms,wasn't sure about the dragstrip with 5 speed? I have heard of alot of vehicles running better times with less engine using the 5 speed?


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## PontiacJim (Dec 29, 2012)

I suspect it depends on the brand of 5-speed. None of them will be inexpensive, and then it goes up from there. The TKO which many opt for is said to be a bit slow to shift in its factory form, but define "slow." You can have this worked so it will shift as fast as you can OR they even have a clutchless version if you care to go that route (check YouTube as I think they have a couple video's showing the TKO shifting). Again, every upgrade is on top of the typical $2,400-$2,500 for just the transmission.

Richmond offers a 5-speed, but don't know much about it and it is very pricey in my book, but it may be an out of the box improvement over the factory TKO without modifying the TKO.

There are also the 6-speeds, but too many gears for me, a Pontiac doesn't need all the gearing when you have good torque - and that is what it boils down to when you select your trans gearing, rear gearing, tire size. Use one of those online calculators to give you a rough idea of the difference between your 4-sp and a 5-sp gearing. There is one calculator that determines 1/4 mile times.

The advantage in the 5-speed is gearing (to include the OD 5th gear), but when you start with a 2.87 first gear found in the TKO-600, you may not be able to use it without smoking tires considering the torque a Pontiac has. That said, suspension mods/adjustments are probably in order to get traction. More traction equals more stress on all driveline components and your chassis -which can mean broken parts or chassis failure. If you don't already have these, you should have at least added the upper/lower control arm supports that tie the two together so you don't rip something out or crack the frame. You may already have these on your car from the factory. 

I would be leary to use a factory 10-bolt for any hard driving unless it was beefed up by the requirements* Pinion head* will tell you you need. He has posted the good 10-bolt build on the forums in the past in order to make them survive -he builds them. A 12-bolt would be a better investment in my opinion.

So, the 5-speed in my opinion will get you a better 1/4 mile time providing you can get your car to hook-up and take advantage of the gear selection, plus allow you to cruise at lower RPM's on the highway with the OD 5th gear.


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## ALKYGTO (Mar 29, 2010)

5 speed won't be any "quicker " just gives od on hwy. So is this a dedicated drag car or just a weekend warrior? For ultimate do it yourself shifting I'm gonna say a Jericho is the way to go. Next up the chain is the Lenco but I don't think that you want to go there.


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## geeteeohguy (Feb 2, 2008)

What Alky said. Jericho might fit your ticket. Not super street friendly, but do-able. It sounds like you already have experience in speed vs power shifting, which is a good thing. There are some pretty good posts on youtube (one guy in a blue '66 GTO in particular) showing the technique and speed involved. I don't like 6 speeds in Pontiacs either, no real use for them. I have not heard from anybody who power/speed shifts a 5 speed, so I don't know how they hold up. I do know a Hurst-shifted Muncie is pretty deadly when set up and driven properly. Keep us posted!


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## geeteeohguy (Feb 2, 2008)

There's a guy on the Corvette forum who goes by "AutoGear". He supplies for "5speeds.com". They build super-case Muncies for racing, among other things. With USA made parts, and special parts, like forged synchros, stronger cases, bigger bearings, forged shift forks, etc. Excellent stuff. Get in touch with 5speeds.com and ask for George. Probably not cheap, but certainly up to the task of repeated power and speed shifts. Good luck.


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## oldskool (Apr 26, 2015)

I suppose the posts in this thread could be considered personal opinions. With that in mind, I'll offer mine. 

I ordered my '69 RA3 GTO with a 2.20 close ratio, and 3.90 gears. Hey, gas was cheap and I didn't do any regular high speed Interstate cruising. 55mph showed about 2900rpm on the hood tach. I put a little over 60,000 miles on it, then raced it for 2 years.

For me, it was the perfect street/strip combo, at the time. Of course, the 4.33 ratio would have been quicker, but too much for the street.

Now the 2.20 1st gear/3.90 rear was great til the Stock rules allowed us to run sticky tires. That required a min of 4000rpm to launch, without a bog. With the sticky tires, I needed a lower 1st gear and a lower rear gear.

So, for racing today, with sticky tires and track, I'd have to recommend a much lower 1st gear. Since you'll still be driving on the street some, I wouldn't change the rear gear. In fact, you can go to maybe 3.23-3.42, to reduce high speed rpm slightly. Or you can run tall street tires and shorter drag tires. Or you can use some combination of different gears and tires heights, to help with your street vs strip set-up.

But, for the trans, I'd go with a heavy duty Muncie, with a really low 1st gear. There is just something "COOL" about driving an old Musclecar and snatching on a 4-speed with a good Hurst shifter, that none of the 5 speeds can match. 

Midwest Muncie makes a drag racing/road racing Muncie that will stand the pressure of racing. They offer several ratios.

Super Pro Road/Drag Race Muncie Super Case M22 Rock-Crusher. SALE !! Save $350 - muncie 4 speeds | muncie transmissions | muncie rebuild kits | muncie gear sets - Midwest Muncie

Muncie Super Duty M23 Super Case 4-speed Drag Racing Rock-Crusher. SALE !! Save $250 - muncie 4 speeds | muncie transmissions | muncie rebuild kits | muncie gear sets - Midwest Muncie


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