73-77 A-body TECH Includes 73GTO, LeMans, Grand Am, Can Am

          
Reply
 
Thread Tools Display Modes
  #1  
Old 06-06-2020, 12:51 AM
BR57's Avatar
BR57 BR57 is offline
Chief Ponti-yacker
 
Join Date: Jul 2006
Location: Toronto, On - Canada
Posts: 648
Default What is the most tire that can be run on the rear of a '73 LeMans?

Time for new tires, my car is running on stock size 14" and I want to change to 15" and something that fills the wheel wells better and can handle the torque of the Canadian Rat under the hood. . I was thinking about going 235 or 245 front and wonder if a rear stagger to 275 is possible with OEM style 15" wheels. What has been the collective experience of the Colonade Community on upgrading tires and wheel sizes?

Attached is a photo of my car as it currently sits on 215x70x14 which would be close to the F70x14 the car came with.
Attached Thumbnails
Click image for larger version

Name:	LeMans GT 73.jpg
Views:	293
Size:	45.6 KB
ID:	541851  

__________________
Ray White
Toronto - Canada
  #2  
Old 06-06-2020, 02:19 AM
73LeMans's Avatar
73LeMans 73LeMans is offline
Chief Ponti-yacker
 
Join Date: Mar 2002
Location: Berkley, MA
Posts: 873
Default

Yeah, never dug the factory wheel and tire width. Always made the poor car look like an elephant on stilts. Great looking car you have there btw, but those 14s in the rear do look like they are begging for some relief.

The factory rim width will be your limiting factor. On the 15" rim, what is that - 7" I think? You'd be pushing 275 on a 9.5" wheel, so that's at least where you'd want to start IMO. You could probably get away with a 245 if it was an 8.5" rim.

__________________
.
Mark S
.
Who needs nice and pretty, when you can have mean and nasty?
KRE Aluminum headed 463CID 73 LeMans. Used to run 10.6x @ 124.55. 3700lbs
.
So much for 2020...shootin for 9s in 2021...and in 2022 apparently.....looks like 2023 as well.
>>My 73 Build thread
  #3  
Old 06-12-2020, 12:26 PM
BR57's Avatar
BR57 BR57 is offline
Chief Ponti-yacker
 
Join Date: Jul 2006
Location: Toronto, On - Canada
Posts: 648
Default

Thanks '73LeMans for your input. I was really hoping for a better response,

Maybe my question should be What tire size are you running on your 73 LeMans?

Hope this gets me some much needed input.

Many thanks,

Ray

__________________
Ray White
Toronto - Canada
  #4  
Old 06-12-2020, 01:40 PM
Keith Seymore's Avatar
Keith Seymore Keith Seymore is offline
Ultimate Warrior
 
Join Date: Nov 2007
Location: Motor City
Posts: 8,182
Default

I used run a 10" wide slick on a Corvette rally (15x8) on my '74 Chevelle.

The frame is the limiting factor. Massage the rail a bit and you can put a 13.5" wide tire on there with no changes to the wheelhouse.

The ones in the photos below are 11.5" on a 10" wide rim.

K



Attached Thumbnails
Click image for larger version

Name:	Chevelle PHR.jpg
Views:	1229
Size:	85.4 KB
ID:	542266   Click image for larger version

Name:	Chevelle rear.JPG
Views:	932
Size:	54.0 KB
ID:	542267  

__________________
'63 LeMans Convertible
'63 Grand Prix
'65 GTO - original, unrestored, Dad was original owner, 5000 original mile Royal Pontiac factory racer
'74 Chevelle - original owner, 9.85 @ 136 mph besthttp://www.superchevy.com/features/s...hevy-chevelle/
My Pontiac Story: http://forums.maxperformanceinc.com/...d.php?t=560524
"Intro from an old Assembly Plant Guy":http://67-72chevytrucks.com/vboard/s...d.php?t=342926

Last edited by Keith Seymore; 06-12-2020 at 02:02 PM.
  #5  
Old 06-12-2020, 02:18 PM
73LeMans's Avatar
73LeMans 73LeMans is offline
Chief Ponti-yacker
 
Join Date: Mar 2002
Location: Berkley, MA
Posts: 873
Default

Man o man, that Chevelle sits perfect.

I'm running a 325/50/15, on a 10" rim. It makes my tires about 12.5" wide. I can still fit a bunch of fingers between the frame and the tire as you can hopefully see in this shot. (space, not fingers)



The frame is not my personal concern. Its the stupid tailpipes that are in my way from getting any wider. If i dumped the exhaust after the muffler, I see no reason why a larger tire can't be made to fit.

__________________
.
Mark S
.
Who needs nice and pretty, when you can have mean and nasty?
KRE Aluminum headed 463CID 73 LeMans. Used to run 10.6x @ 124.55. 3700lbs
.
So much for 2020...shootin for 9s in 2021...and in 2022 apparently.....looks like 2023 as well.
>>My 73 Build thread
  #6  
Old 06-12-2020, 03:55 PM
PurelyGTO68 PurelyGTO68 is offline
Chief Ponti-yacker
 
Join Date: Jul 2015
Posts: 792
Default

We run 275 tires on our 73 LeMans 400 with original 15" rally II wheels.

  #7  
Old 06-12-2020, 04:37 PM
BR57's Avatar
BR57 BR57 is offline
Chief Ponti-yacker
 
Join Date: Jul 2006
Location: Toronto, On - Canada
Posts: 648
Default

Thanks fellas, this is all good information and is what I was looking for, much appreciated.
I'd agree on Keith's Chevelle, the car looks amazing !

__________________
Ray White
Toronto - Canada
  #8  
Old 06-12-2020, 07:22 PM
Big Bear's Avatar
Big Bear Big Bear is offline
Senior Member
 
Join Date: Feb 2014
Location: Ont Canada
Posts: 132
Default

Back in the seventies the GA had 10" rims with L-50s. Rolled the wheel lip and tires didnt rub. Now I see it in Toronto with 15" rallies. Tire size unknown
Attached Thumbnails
Click image for larger version

Name:	scan0008.jpg
Views:	254
Size:	54.4 KB
ID:	542291   Click image for larger version

Name:	thumbnail (7).jpg
Views:	286
Size:	58.7 KB
ID:	542292  

  #9  
Old 06-18-2020, 12:12 PM
moontower69's Avatar
moontower69 moontower69 is offline
Chief Ponti-yacker
 
Join Date: Jul 2007
Posts: 522
Default 245/60/15 BFGs

is what I run on my 74 Lemans and it does touch the muffler in rear and shines up the tie rod in the front, but works great. That's the biggest without any mods you can run.

__________________
1974 Lemans Sportecoupe GT (daily driver)

"Well the girls out there knock me out, you know
Cruisin' around in my GTO"

Rock 'n' Roll High School
Ramones
  #10  
Old 06-20-2020, 07:47 AM
cdrookie cdrookie is offline
Chief Ponti-yacker
 
Join Date: Apr 2006
Location: NW PA
Posts: 740
Default

Quote:
Originally Posted by moontower69 View Post
is what I run on my 74 Lemans and it does touch the muffler in rear and shines up the tie rod in the front, but works great. That's the biggest without any mods you can run.

I ran 325/50-15 on the rear and 275/60-15 on the front on 15x10 and 15x8 wheels. Your wheel backspace is wrong if you're rubbing.

  #11  
Old 06-27-2020, 01:23 PM
BR57's Avatar
BR57 BR57 is offline
Chief Ponti-yacker
 
Join Date: Jul 2006
Location: Toronto, On - Canada
Posts: 648
Default

After all this good input and test fitting wheels and tires I have ordered Radial T/As 255x60x15 rear with 15x8 wheels and 235x60x15 front with 15x7 wheels. 4.25 backspacing. Here's some pictures, once the project is done I will post more.
Attached Thumbnails
Click image for larger version

Name:	thumbnail_IMG_20200619_1615595.jpg
Views:	183
Size:	61.5 KB
ID:	543555   Click image for larger version

Name:	thumbnail_IMG_20200619_1349530.jpg
Views:	178
Size:	61.7 KB
ID:	543556   Click image for larger version

Name:	thumbnail_IMG_20200619_1351578.jpg
Views:	195
Size:	69.4 KB
ID:	543557  

__________________
Ray White
Toronto - Canada
  #12  
Old 06-27-2020, 08:24 PM
73LeMans's Avatar
73LeMans 73LeMans is offline
Chief Ponti-yacker
 
Join Date: Mar 2002
Location: Berkley, MA
Posts: 873
Default

Thats going to look real nice!!!

__________________
.
Mark S
.
Who needs nice and pretty, when you can have mean and nasty?
KRE Aluminum headed 463CID 73 LeMans. Used to run 10.6x @ 124.55. 3700lbs
.
So much for 2020...shootin for 9s in 2021...and in 2022 apparently.....looks like 2023 as well.
>>My 73 Build thread
  #13  
Old 06-30-2020, 12:09 PM
moontower69's Avatar
moontower69 moontower69 is offline
Chief Ponti-yacker
 
Join Date: Jul 2007
Posts: 522
Default I run 255/60/15 on Rally IIs

With no mods on stock springs and shocks, slightly touches exhaust and front sway bar on tight turn but no issues. Drives great, very planted. That's the biggest I've been able to get on 15x7 Rallys - can go bigger with 15x8 which WHEEL VINTIQUE makes
Attached Thumbnails
Click image for larger version

Name:	IMG_8419.jpg
Views:	225
Size:	65.2 KB
ID:	543822   Click image for larger version

Name:	IMG_5300.jpg
Views:	208
Size:	98.3 KB
ID:	543823  

__________________
1974 Lemans Sportecoupe GT (daily driver)

"Well the girls out there knock me out, you know
Cruisin' around in my GTO"

Rock 'n' Roll High School
Ramones
  #14  
Old 07-02-2020, 12:16 AM
BR57's Avatar
BR57 BR57 is offline
Chief Ponti-yacker
 
Join Date: Jul 2006
Location: Toronto, On - Canada
Posts: 648
Default

Received this photo on my Instagram feed today. Don't know tire size but in terms of look this car has just the right amount of Badassery that I'm looking for.
Attached Thumbnails
Click image for larger version

Name:	Badass 73 GTO.jpg
Views:	240
Size:	90.2 KB
ID:	543983  

__________________
Ray White
Toronto - Canada
  #15  
Old 07-02-2020, 09:39 AM
cdrookie cdrookie is offline
Chief Ponti-yacker
 
Join Date: Apr 2006
Location: NW PA
Posts: 740
Default

IMO that car does have the look, but could look more badasser. It's hard to tell without a straight side shot but I'd drop the front a few inches and the back an inch or so. I'd put 10" wheels on the back with taller wider tires. I'm guessing those are 7" wide factory wheels and probably 70 series tires. The wheel wells on these cars are HUGE and need to be filled up to look correct. I'd love to put some MT 315/60-15 meats on the back of my Lemons. Even though they are DOT approved I'm not sure how much street use they'd handle.

  #16  
Old 07-02-2020, 11:02 AM
moontower69's Avatar
moontower69 moontower69 is offline
Chief Ponti-yacker
 
Join Date: Jul 2007
Posts: 522
Default BFG 275 60R/15 on back and 235/60/15 on front

That's a bad ass look if you can fit the rears on a custom rim....

__________________
1974 Lemans Sportecoupe GT (daily driver)

"Well the girls out there knock me out, you know
Cruisin' around in my GTO"

Rock 'n' Roll High School
Ramones
  #17  
Old 07-09-2020, 12:41 AM
BR57's Avatar
BR57 BR57 is offline
Chief Ponti-yacker
 
Join Date: Jul 2006
Location: Toronto, On - Canada
Posts: 648
Default

Do you like pictures of progress on the project?

Used Duplicolor GM Royal Blue to get a good match of the paint for the wheels then Armstrong'd the tires on the wheels tonight, have to take them to a shop for balancing. Getting closer.
Attached Thumbnails
Click image for larger version

Name:	Wheels IMG_20200705_2024061.jpg
Views:	223
Size:	89.6 KB
ID:	544576   Click image for larger version

Name:	IMG_20200708_2338477.jpg
Views:	206
Size:	90.8 KB
ID:	544577  

__________________
Ray White
Toronto - Canada
  #18  
Old 07-10-2020, 02:49 PM
73LeMans's Avatar
73LeMans 73LeMans is offline
Chief Ponti-yacker
 
Join Date: Mar 2002
Location: Berkley, MA
Posts: 873
Default

Cant wait to see it all done!

__________________
.
Mark S
.
Who needs nice and pretty, when you can have mean and nasty?
KRE Aluminum headed 463CID 73 LeMans. Used to run 10.6x @ 124.55. 3700lbs
.
So much for 2020...shootin for 9s in 2021...and in 2022 apparently.....looks like 2023 as well.
>>My 73 Build thread
  #19  
Old 07-10-2020, 08:49 PM
BR57's Avatar
BR57 BR57 is offline
Chief Ponti-yacker
 
Join Date: Jul 2006
Location: Toronto, On - Canada
Posts: 648
Default

Here's a couple of photos, left off the caps for now, used chrome nuts. I thought the big meats would be harder to spin but she still burns out rather easily, there's a lot of torque under my hood.

Thanks to everyone for their advice and input it was very helpful. The rears are 255 60 15 and on the passenger side there is a finger width to the tailpipe, drivers side has lots of clearance though. Overall I'm very pleased with the results.
Attached Thumbnails
Click image for larger version

Name:	thumbnail_IMG_20200710_1954591.jpg
Views:	240
Size:	65.9 KB
ID:	544714   Click image for larger version

Name:	thumbnail_IMG_20200710_1948307.jpg
Views:	225
Size:	59.1 KB
ID:	544715   Click image for larger version

Name:	42582c1f-5ba1-4f8b-ab2f-7b3b50de5e13IMG_20140823_174500.jpg
Views:	216
Size:	71.6 KB
ID:	544716  

__________________
Ray White
Toronto - Canada
  #20  
Old 07-10-2020, 10:00 PM
73LeMans's Avatar
73LeMans 73LeMans is offline
Chief Ponti-yacker
 
Join Date: Mar 2002
Location: Berkley, MA
Posts: 873
Default

Car looks great. It really transforms the whole look. Wow. Nicely done.

We can fix that problem under the hood if you want....😁😁😁😁

__________________
.
Mark S
.
Who needs nice and pretty, when you can have mean and nasty?
KRE Aluminum headed 463CID 73 LeMans. Used to run 10.6x @ 124.55. 3700lbs
.
So much for 2020...shootin for 9s in 2021...and in 2022 apparently.....looks like 2023 as well.
>>My 73 Build thread
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 03:39 AM.

 

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