#1  
Old 01-19-2022, 02:04 PM
ponchorob ponchorob is offline
Senior Chief
 
Join Date: Aug 2007
Location: Austria vienna
Posts: 299
Default 428 street strip gear

428 with 13 heads 60919 cam rhoads lifters 9.6 compression. 67 firebird 2500 Converter... thought about using a 3.90 gear...for street strip.... if a take or go back to 3.42 ill think i would runner slower maybe 0.3 to 0.4 s..... so what do guys think about 3.42 vers 3.90 gears on my combo

  #2  
Old 01-19-2022, 03:34 PM
johnta1's Avatar
johnta1 johnta1 is offline
Ultimate Warrior
 
Join Date: Feb 2001
Location: now sunny Florida!
Posts: 21,237
Default

I'd say the 3.90 would be more strip than street.
3.42's would make great street and some strip or even more strip.



__________________
John Wallace - johnta1
Pontiac Power RULES !!!
www.wallaceracing.com

Winner of Top Class at Pontiac Nationals, 2004 Cordova
Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats

KRE's MR-1 - 1st 5 second Pontiac block ever!


"Every man has a right to his own opinion, but no man has a right to be wrong in his facts."

"People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates
  #3  
Old 01-19-2022, 03:47 PM
Mike Davis's Avatar
Mike Davis Mike Davis is offline
Ultimate Warrior
 
Join Date: Jun 2000
Location: Athens Ga, or at a NMCA race
Posts: 1,994
Default

3.55 or 3.73 works well with a 4" stroke.
I switched from 3.73 to 3.90 to 4.10 and noticed very little difference in ET.
Roughly less than a .10 between the 3.

__________________
66 GTO Nostalgia Super Stock/Street Legal Car
421 CID, stock block, Wenzler Intake, 2- Carter 750 AFB's, 3.90 Gears, Full Factory Interior, Full Exhaust, Stock Suspension 3750LBS 9.77@136.99
Multiple NSCA/NMCA World Champion

66 GTO 389 3x2, 4 speed, 4.33 gear, Montero Red 33K original Miles
67 GTO 2dr Post, 428, Tri Power, 3.55 Gears
80 Trans Am Black SE Y84 W72 WS6
The Following User Says Thank You to Mike Davis For This Useful Post:
  #4  
Old 01-19-2022, 04:01 PM
nas t eh nas t eh is online now
Senior Chief
 
Join Date: Jun 2015
Location: Edmonton Alberta
Posts: 272
Default

Three speed auto or four speed overdrive? 3.42 if turbo 400, 3.90 if you have an OD trans.

  #5  
Old 01-19-2022, 04:10 PM
ponchorob ponchorob is offline
Senior Chief
 
Join Date: Aug 2007
Location: Austria vienna
Posts: 299
Default

Have a th400 ....

  #6  
Old 01-19-2022, 04:25 PM
ponchorob ponchorob is offline
Senior Chief
 
Join Date: Aug 2007
Location: Austria vienna
Posts: 299
Default

Have a th400 ....

  #7  
Old 01-19-2022, 04:34 PM
PONTIAC LARRY's Avatar
PONTIAC LARRY PONTIAC LARRY is offline
Ultimate Warrior
 
Join Date: Jan 2004
Location: Republic of Texas , Ellis County
Posts: 2,107
Default

Quote:
Originally Posted by ponchorob View Post
428 with 13 heads 60919 cam rhoads lifters 9.6 compression. 67 firebird 2500 Converter... thought about using a 3.90 gear...for street strip.... if a take or go back to 3.42 ill think i would runner slower maybe 0.3 to 0.4 s..... so what do guys think about 3.42 vers 3.90 gears on my combo
3.42 plus adv +4 on the chain...

__________________
63 Catalina coupe 455 budget drag car 11's 1/4 , 7.4 1/8th
66 Star Chief Executive 57k mile
69 Le Mans 2 dr HT 350 85k mile 15 sec 1/4
69 Firebird 400 Burgandy/Black
70 Olds Rallye 350 F85 4 speed 3.91's
70 Olds Cutlass Cruiser Red Wagon 350 101k miles 15 sec 1/4 12 sec w 455
74 Cheyenne Super C10 LWB Gen 6 454 w ZZ502 cam 3.07gear 13.1 1/4, 8.3 1/8
2020 RAM 1500 SLT 4x4 5.7 A8 Hemi
2007 Hummer H3 3.7 liter turd
2019 Chevy Spark petrol car 38 mpg
  #8  
Old 01-19-2022, 04:49 PM
nas t eh nas t eh is online now
Senior Chief
 
Join Date: Jun 2015
Location: Edmonton Alberta
Posts: 272
Default

Quote:
Originally Posted by ponchorob View Post
Have a th400 ....
3.90 is rather short for hyway speeds on the Street, stick with 3.42

  #9  
Old 01-19-2022, 06:28 PM
dragracerx2813's Avatar
dragracerx2813 dragracerx2813 is offline
Chief Ponti-yacker
 
Join Date: Aug 2016
Location: Orange Park Fl
Posts: 540
Default

What Mike Davis said.

  #10  
Old 01-19-2022, 06:56 PM
ponchorob ponchorob is offline
Senior Chief
 
Join Date: Aug 2007
Location: Austria vienna
Posts: 299
Default

Mike davis 3.73 to 4.10 results are interesting but maybe his converter stalls a lot higher than mine...so theres not so much difference

  #11  
Old 01-19-2022, 07:18 PM
ponchorob ponchorob is offline
Senior Chief
 
Join Date: Aug 2007
Location: Austria vienna
Posts: 299
Default

....i mean with my 2500 converter it should run a lot faster with 3.90 vers 3.55 but maybe im wrong..

  #12  
Old 01-19-2022, 07:59 PM
Mike Davis's Avatar
Mike Davis Mike Davis is offline
Ultimate Warrior
 
Join Date: Jun 2000
Location: Athens Ga, or at a NMCA race
Posts: 1,994
Default

I have a 5200 Converter in my 66 with the 421.
When it was primarily a street car I had a 3500 in it and a 3.73 gear. Was a good combo for around town and short drives.

With the cam shaft you are running I'd go 3.55 if you can.
My 67 has a 428, #62 casting heads, 66 Tri Power, Ultradyne Cam similar to the 60919, TH400 with a 2700 Converter, 3.55 gears with a 27" tire. I like the way it cruises on the highway. I would not want much more than that.
Attached Thumbnails
Click image for larger version

Name:	image000000 (8).jpg
Views:	120
Size:	74.2 KB
ID:	582242  

__________________
66 GTO Nostalgia Super Stock/Street Legal Car
421 CID, stock block, Wenzler Intake, 2- Carter 750 AFB's, 3.90 Gears, Full Factory Interior, Full Exhaust, Stock Suspension 3750LBS 9.77@136.99
Multiple NSCA/NMCA World Champion

66 GTO 389 3x2, 4 speed, 4.33 gear, Montero Red 33K original Miles
67 GTO 2dr Post, 428, Tri Power, 3.55 Gears
80 Trans Am Black SE Y84 W72 WS6
  #13  
Old 01-20-2022, 04:34 AM
ponchorob ponchorob is offline
Senior Chief
 
Join Date: Aug 2007
Location: Austria vienna
Posts: 299
Default

Guys thanks fot all your opinions an Mike thanks for your detailed info ..

  #14  
Old 01-20-2022, 08:53 AM
Half-Inch Stud's Avatar
Half-Inch Stud Half-Inch Stud is offline
Ultimate Warrior
 
Join Date: Jul 2000
Location: BlueBell, PA or AL U.S.A.
Posts: 18,457
Default

see 12.24 ET signture, only combo diff is the stroke.

__________________
12.24/111.6MPH/1.76 60'/28"/3.54:1/SP-TH400/469 R96A/236-244-112LC/1050&TorkerI//3850Lbs//15MPG/89oct

Sold 2003: 12.00/112MPH/1.61 60'/26"x3.31:1/10"/469 #48/245-255-110LSA/Q-Jet-Torker/3650Lbs//18MPG 94oct
Sold 1994: 11.00/123MPH/1.50 60'/29.5"x4.10:1/10"/469 #48/245-255-110LSA/Dual600s-Wenzler/3250Lbs//94oct
  #15  
Old 01-20-2022, 02:52 PM
RBAILEY RBAILEY is offline
Member
 
Join Date: Oct 2021
Posts: 87
Default

3.42

  #16  
Old 01-20-2022, 02:54 PM
RBAILEY RBAILEY is offline
Member
 
Join Date: Oct 2021
Posts: 87
Default

3.42 good choice for street strip.....3.90 is too low..w/TH400. If your tire height is anything shorter than 28 you'll be hating life on the freeway with 3.90s, and even with 28s its not fun on the freeway with 3.90s

  #17  
Old 01-21-2022, 01:26 PM
ponchorob ponchorob is offline
Senior Chief
 
Join Date: Aug 2007
Location: Austria vienna
Posts: 299
Default

Mike your 67 428 with 3.55 gear have you ever run on the track any quartermile results....?

  #18  
Old 01-21-2022, 01:49 PM
Mike Davis's Avatar
Mike Davis Mike Davis is offline
Ultimate Warrior
 
Join Date: Jun 2000
Location: Athens Ga, or at a NMCA race
Posts: 1,994
Default

I have not run the 67 in a long time or with this combo. Just basically a cruiser now. It has been in the family since new.
The last time the car was ran, my Dad ran it in the 90's. Combo was 428 std bore, 068 cam, stock 670 heads, Ram Air Manifolds, 67 Q jet intake and carb, TH400, 3.55 gear. Car ran 12.70's.

__________________
66 GTO Nostalgia Super Stock/Street Legal Car
421 CID, stock block, Wenzler Intake, 2- Carter 750 AFB's, 3.90 Gears, Full Factory Interior, Full Exhaust, Stock Suspension 3750LBS 9.77@136.99
Multiple NSCA/NMCA World Champion

66 GTO 389 3x2, 4 speed, 4.33 gear, Montero Red 33K original Miles
67 GTO 2dr Post, 428, Tri Power, 3.55 Gears
80 Trans Am Black SE Y84 W72 WS6

Last edited by Mike Davis; 01-21-2022 at 01:58 PM.
  #19  
Old 01-21-2022, 03:32 PM
chiefbigb chiefbigb is offline
Ultimate Warrior
 
Join Date: Dec 2003
Location: richmond va usa
Posts: 1,479
Default

Gear vendor would allow you to run more gear and cruise on the interstate.

__________________
Be carefull of the feet you step on today.They may be attached to the a$$ you kiss tomorrow.
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:09 PM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017