[70 Dream]

Robert, I think he's saying with an OD 5th gear ratio of approx .64 to 1, then the 4.56 rear gears convert to approx 3.08s

[tom s]

EXACTLY what I was trying to relate.Thanks,Tom

[Junkyard Dog]

Originally Posted by tom s

Robert,IMO a 2.20 first gear for a pontiac is all but useless.With a large cam and anything but 4.10 or lower gears sucks.Bin there done that.

Really depends on engine combo. My 66 GTO came with a 455, 96 heads, and a 744 cam. It had a 2.2 ratio first gear, and a 3.55 rear gear. It would light up the tires while driving in first or second without touching the clutch. Just roll into the throttle and the tires would start screaming. Indeed, first gear was useless for anything but squealing tires.

Maybe it would be different at the track, but this is the street section.

Tom, you really have me wanting a Tremec for the new engine combo, though.

[Junkyard Dog]

What were the lowest and highest gears Pontiac ever put behind its traditional engines?

My guess is 2.41 and 4.33.

Am I right?

The Tremec TKO600 with a 3.55 gear mimics a Muncie/4.63 gear combo in first.

The Tremec with a 3.55 gear mimics a Muncie/2.27 gear combo in overdrive.

Both higher and lower than anything Pontiac put in.

3.73 Gear with the Tremec would be like a 4.86 and a 2.38 rear gear in first and overdrive.

4.10 Gear with the Tremec would be like a 5.34 and a 2.62 rear gear in first and overdrive. (but one might start running out of rpm at the end of the track?)

4.33 Gear with the Tremec would be like a 5.64 and a 2.77 rear gear in first and overdrive.

4.56 Gear with the Tremec would be like a 5.94 and a 2.91 rear gear in first and overdrive.

Hard to believe you won't run out of rpm in the quarter mile with a 4.56 gear. Are you running a 455? Your car must be a lot of fun on the starting line!

[tom s]

running a 421 60 over,leave at 6000,shift at or ABOUT 6200.Things happen REAL fast in first.Thats what hurts my 60 ft as I get virtually no pull before I need to shift.I did not have a 4.30 avail when I built the car and the only 1st gear at that time was the 3.27.Did try a 4.10 and the 56 ran the best.The motor has a bathtub tunnel ram with a pair of 750s.The 4.10s were not good for me on the street as I could not use 5th gear in most of my driving conditions.The 56s with a 30in tire would be perfect IMO.Tom

[form406]

what does my 308 with 15" 50 series tires come out to...? i seem to have enough to play on the freeway with the 5th gear guys...

[bobzdar]

I really don't understand people having problems with say 3.55's on the highway, especially in a 400. 3000rpm at cruising speed is average to low for most modern (4 cyl) cars, the difference is they have decent sound insulation and/or quiet exhausts. If 3000rpm on the highway bugs you, try some quieter mufflers. A lot cheaper than a rear end swap and no loss of acceleration.

A good friend of mine has a 455 powered lemans with 3.31 gears and a th350, 80mph cruising is not a problem and he is going over 3000rpm. He's made the 8 hour trip to Norwalk 3 times. 3.31's would be even less a big deal in a 400, but 3.55's would give around the same effective piston speed etc.

Fwiw, my '78 t/a has 3.23's and a 400/4 speed, I get 20mpg highway mileage and if I were not into road racing vs. drag racing, I wouldn't hesitate to go with 3.73's.

[70 Dream]

Bobz, I guess my biggest complaint is not noise, it is that at 3200/65, it feels like I'm dragging an anchor on a rope tied to the rear bumper, like it's trying to keep me from moving forward . . . .

like the guys said above, I have this continuing urge to shift one more gear higher . . . . . . except there isn't one . . . .

and if I want to go 80, I'm at 4000

too many rpm . . . . . . .

[Robert Imhof]

Question...my car currently has a muncie in it. How much will it cost after it is all set and done approximately? I ask this because on the classic 5 speed Chevy website it has a deluxe kit which says "A popular option for 4-speed to 5-speed conversions" and this costs in the $2500 range. Their elite kit says "A popular option for automatic to 5-speed conversions" but it includes new clutches, flywheel etc. and it costs in the $3600+ range.

http://www.classicchevy5speed.com/68..._Selection.htm

[gearbanger]

Minimum you need a clutch disc with 26 splines, $50. You will need the kit, $2500. If you are using a console you'll need the offset shifter, $300. You'll need some time and some metal fabrication skills. Otherwise you'll need some more $. You'll probably need new carpet because the tunnel will be a little biger in the end and the carpet might not reach. $100 So probably $3000 by the time its all said and done.

[gearbanger]

If you guys are using 2.52 for first gear comparison, then you must have m-21's or m-22's. I had an M20 so it had a 2.52. 1st in the TKO600 is a little lower but not that much. With 3.55's it's about like my muncie with 4.10s. Which I really liked when I had that before.

tom s

I am not dogging you, I am just trying to figure this out for my own infrmation as well. Why do you have you car geared that low? Did you try different combinations of gears and that is the best for drag racing? Because it seems like you have pretty much eliminated your first gear from being usable with that gearing. You could launch in second and it would be like an M20 muncie with 3.55 gears! If you have figured out something please let us know about it. I love your car and it looks like it would run like a raped ape, I just want to be getting the best out of my combo too. I have been trying to figure out what would be the best way to get my car going on the street. I am basically building a street car that I can run at the strip in the same trim and be able to get respectable 60 ft times and ETs. And cruise the interstates with it too.

[tom s]

actually my car does not like starting out in second with the 3.90s.I usually drive 1st,3rd and 5th on the street.Never tried 2nd at the strip with the 4.56s.My engine combo just does not like to run under 2000RPMs in 5th gear and dont want to drive around town at 50MPH in 4th.ANYTIME anyone is in the SoCal area,all my cars are avail to drive.I like big cams and like to be able to drive them on the street.I just had to change cams in my 455 RA V GTO with a wide muncie and 3.55 gears because it SUCKED to drive.Cam was 252-262@60 with 660 lift.With 3.90s or 4.10s it would have been fine.Dropped to 236-246 and it drives great.EVERYTHING on a street car that goes to the races once or twice a year is a compremise.I change cams and gears a lot just to try and find what I LIKE.Someone else might hate it.I built the 421 Tempest like it was going to be a 4speed race car on pump gas and added the OD to make it street drivable.Like I said before I think the 4.30s will be what I want but did not have them when I built the car.Had 4.10s and 4.56s and my car performed better with the 56s than the 10s.I think I can take my tunnel ram off and put on a high rise 2-4 and run quicker but would loose the WOW factor and am NOT willing to do it.The high rise intake makes 30HP less but is better across the RPM range so would be quicker.Tom

[tom s]

I have NO traction problems now!I leave at 6000 and pull the the handle.Might have a problem with the taller first gear.Tom

[Junkyard Dog]

You launch at 6,000 RPM? Why are you babying it?

[tom s]

if it made HP at 7000 I would leave there!LOL FYI,I saw that the White Warrior has 5.13s in the back with a 3.05 first gear Jerico,he leaves on the rev limiter.Think he goes through the lights at 8000.Ran 9.0s.Same car with a lot more motor BUT on the nuts,no juice.Tom